Vehicle Repairs during Emergency

Enough to fill a trailer and then some. I just need a trailer. A mobile shop would be nice but until then I have to pack around a few tool boxes and hope I have what I need to fix my rigs on the trails.

 

Automotive Belts & Hose

by Larry Carley c2005

According to the Car Care Council, nearly 30% of the vehicles they have inspected have belts and/or hose that need replacing. Yet in most cases, the vehicle owners were totally unaware of the condition of these parts.

Everybody wants a reliable vehicle to drive, but not many people are forward-thinking enough to practice preventive maintenance beyond the barest of basics. After all, preventive maintenance costs money and nobody likes to spend money "unnecessarily." We put unnecessarily in quotes because we want to emphasize the fact that most consumers do not appreciate the benefits of preventive maintenance when it comes to belts and hose. Changing the oil and filters every so often they can understand. Oil and filters get dirty and need to be changed. Replacing spark plugs periodically they can also understand. Spark plugs wear out and can become fouled. But replacing radiator and heater hose that have not yet failed? No way.

What people often learn the hard way is that belts and hose age, and what happen when they fail. The coolant leaks out and the engine overheats.

Most belts and hose fail from the inside out. Rubber hose (which are actually made of neoprene and other synthetic materials) deteriorate with age and exposure to heat. The hose material can become hard and brittle. Tiny cracks develop in the rubber which eventually cause the hose to split, blister or leak. Oil on the outside of coolant hose can also accelerate the breakdown of the hose material. This type of deterioration can usually be seen on the outside. But what often escapes detection is what is going on inside hose.

Today's bimetal cast iron/aluminum engines and aluminum radiators can create conditions that set up an electrical current in the coolant. The inside surface of the hose becomes a conductor, which causes the material to pit and weaken. Cracks and striations tend to form near the ends of the hose that eventually eat through from the inside out causing the hose to fail. Yet until the failure occurs, the hose may look good as new on the outside.

This type of deterioration can sometimes be identified by pinching hose near each end with your thumb and fingers. If you feel "ridges" or "voids" inside the hose, it is experiencing electro-chemical degradation (ECD) and needs to be replaced. But even this type of inspection may not catch all the bad hose that are out there.

HOSE REPLACEMENT

Replacement hose must be the same type, size and length as the original. Original equipment ring type clamps (which may lose tension with age) on coolant, fuel, vacuum or emissions hose should be replaced with screw clamps.

If a coolant hose does not seem to fit properly, try switching it end for end. The inside diameters of the ends may be different depending on the application. Molded hose is also designed to fit one way.

Never pry a coolant hose loose with a screwdriver or similar tool. Doing so can crush or damage the pipe connections on the heater core or radiator, creating a potential leak path. If the hose won't come off, it should be slit with a knife and peeled off.

A good time to replace coolant hose is when changing the water pump or radiator. New hoses might also be needed if the engine itself is being replaced or overhauled.

When replacing an upper radiator hose, pay close attention to the condition of the thermostat housing, too. Aluminum housings can become badly corroded with age and may not seal properly when the new hose is installed. If the housing is pitted and rough, replace it.

HOSE DESIGN

Fuel, emissions and vacuum hose are made of special materials because of the liquids and vapors they carry. Fuel hose is made to withstand gasoline and alcohol, and is reinforced to hold pressure.

A fuel hose is usually good for up to five years of service. The reason they need replaced is due to internal flaking of the hose which releases small pieces of rubber that can end up plugging fuel injectors or carburetor circuits.

The pressure rating is printed on the hose, so be sure you use the correct type of fuel hose for the application. Hose that is pressure rated for carbureted engines (7 to 10 psi) must never be used on fuel injected engines (35 to 80 psi or higher). The higher rated EFI hose can always be used on a carbureted application but never the reverse.

High pressure EFI hose often require special high pressure "rolled edge" clamps rather than standard clamps or spring clamps. Some EFI hose also use special connectors.

PVC emissions hose is designed to withstand oil and fuel vapors, but is not designed to handle internal pressure like fuel hose.

Emission hose need replaced when age-weakened rubber collapses under vacuum, which prevents the necessary venting of crankcase blowby vapors through the PCV valve. Hose also will become plugged with accumulated crud that blocks the flow of air through the PCV system, causing sludge to build up rapidly in the crankcase. If not corrected, this can lead to oil breakdown and major engine damage for the customer.

The PCV hose should be inspected (and replaced if necessary) when the PCV valve is inspected (typically every 30,000 to 50,000 miles).

Vacuum hose are designed not to collapse under vacuum, but they are not intended for carrying liquids, gasoline or oil. So be sure to use the correct hose application for the job.

Replacement of vacuum hose is important in the sense that if one develops a leak, it can lead to all kinds of driveability and emissions headaches.

Fairly expensive when compared to other types of hose, power steering hose usually is not replaced unless it is leaking. However, power steering needs to be inspected periodically for leaks or damage because such a hose failure can cause a loss of power steering assist.

Power steering hose comes in two varieties: low pressure hose for the return line, and high pressure for the supply side. Using the right hose is critical. Flushing the power steering pump, hose and steering gear is also recommended after hose replacement if the old hose were flaking internally.

Air conditioning hose comes in two basic types: barrier and nonbarrier. The latter is okay for older vehicles that have R-12 A/C systems, but is not recommended for newer vehicles or those that have been converted to R-134a refrigerant. If a leaky A/C hose is found to contain sludge or debris, the system should be flushed and an in-line filter installed to prevent orifice plugging and to protect the compressor.

BELTS

Belts likewise deteriorate with heat and mileage. Every time a belt passes around a pulley, it bends and flexes. This produces heat in the belt which hardens the rubber over time. The wear process can be greatly accelerated if the belt is loose and slips. The additional friction between belt and pulley will make a belt run even hotter. After millions of such journeys around the pulleys, even the best drive belt begins to suffer the effects of age. The rubber begins to crack and fray, and the internal cords become weakened and brittle. Eventually the belt breaks, and at that point, all cooling is lost along with whatever other functions were powered by the belt (water pump, alternator, power steering, air conditioning, etc.).

You can't always determine a belt's true condition by appearances alone. Any belt that is obviously cracked and frayed should be replaced. But with many of today's "bandless" belts, there is no outside cover to peel loose and betray the belt's deteriorated condition. A belt may appear to be like new on the outside yet be on the verge of failure because of weakened cords inside.

Most V-belts look the same on the outside, though there are significant differences inside that affect the life of the belt. One of the most obvious differences is in the placement of the tensile cords that hold the belt together and prevent stretching. Tensile cords are usually made of twisted polyester and run the length of the belt. Additional reinforcement is provided in the "undercord" area of most belts through the use of crosswise layers of fabric. Some manufacturers use chopped fibers blended into the rubber.

Placement of the reinforcing tensile cords in the belt can affect belt life. One can see where the larger cords are placed by looking at the sides of the belt. "Center cord belts" have the tensile cords near the center and are less costly to manufacture because they produce less waste during cutting and trimming operations. Other belts, called "high cord belts," have the cords positioned closer to the top.

Positioning the cords at the widest part of the "V" allows up to 40% more reinforcing cords to be used, which makes for a stronger belt. Therefore, high cord belts usually last about four times longer than center cord belts.

But all high cord belts are not long-life belts. If the manufacturer uses low-quality materials and does not get a good cure when the belt is vulcanized, that particular high cord belt may not last as long as a center cord belt.

Another variation in V-belt designs is the notched belt. Though not used as original equipment, it is offered as an aftermarket replacement. The notches make the belt more flexible, which reduces friction and heat buildup as the belt bends around the pulleys. The notches also help to dissipate heat, and the cooler the belt runs, the longer it lasts.

A modification on this theme is a notched V-belt with the cogs facing out instead of in toward the pulleys. One manufacturer says reversing the cogs aids cooling even more, which can help the belt outlast conventional V-belts.

The problem that is guaranteed to shorten belt life is slippage. Slippage creates heat that glazes and hardens the belt, making it more prone to cracking and premature failure. Symptoms of slippage are noise or chatter, and it is evident by viewing glazed or shiny sidewalls on the belt.

Serpentine belts (flat ribbed belts), which are also called "Poly-V, Poly-Rib and Micro V" are so named because of the snake-like path they often follow around the pulleys. The flat design reduces heat buildup in the belt so the belt generally lasts longer than a comparable V-belt. A recommended replacement interval for serpentine belts suggested by one manufacturer is every 50,000 miles, or sooner if the belt has become glazed and is making noise.

A loose belt should be retensioned back to the manufacturer specs using a tension gauge. The old rule of thumb about leaving a half inch of deflection between the two furthest pulleys is not very accurate, and, unless a gauge is used, there is no way to know if the belt is too tight or not tight enough. Too much tension on the belt increases strain on the tensile cords, which shortens the life of the belt, as well as the life of the shaft bearings on the accessories.

Deep cracks in a belt are usually an indication of age. Such a belt is likely to fail soon and should be replaced. But cracks may also indicate an undersized alternator pulley (the alternator may have been replaced previously). The smaller the radius of a pulley, the more the belt flexes with each revolution. This increases heat buildup and shortens the life of the belt. If the pulley grooves are worn or if the belt is too narrow for the application, that can also make a belt ride too low in the pulley. A belt should ride flush to 1/16" above the edge of the pulley.

A misaligned pulley is usually the culprit for a twisted and reversed belt. Pulleys should be parallel and be within 1/8" of alignment of each other. Alignment can be checked with a straight edge. If a pulley is cocked slightly with respect to the rest, it can twist the belt and turn it inside out.

A loose belt or one with broken cords inside can also twist. With a serpentine belt, a misaligned pulley may throw the belt or wear away the belts directional ribs.

BELT PRECAUTIONS

Probably the fastest way to ruin a new belt is to "stretch" a V-belt over a pulley instead of loosening the accessory designed to slip it into place. As mentioned earlier, the tensile cords in the belt are there to prevent it from stretching. Forcing it over a pulley can break these cords, causing the belt to fail soon thereafter.

Oil and grease can also ruin belts. Petroleum-based lubricants attack rubber and cause it to become soft and spongy. Oil also attracts dirt and grit which can act like an abrasive against the belt. Noise, however, is always an indication of trouble, and the cause, not the symptom, should be treated. Noise may indicate a loose belt, a misaligned or bent pulley, bad shaft bearings in the water pump, alternator or another accessory.

A burr or nick in a pulley can also cut short the life of a new belt. These pulley imperfections will scour the sides of the belt and wear streaks into it. The belt will lose tension, slip and wear all the faster.

When replacing belts, keep in mind they must be the same type, width and length as the belts being replaced. Compare the old and new belts to make sure. V-belts should be adjusted and checked with a tension gauge. Most serpentine belts have an automatic tensioner making adjustment unnecessary.

When replacing a serpentine belt with a spring-loaded idler pulley, check the condition of the tensioner if the old belt was glazed and making noise. Loss of tension with accumulated mileage is not unusual, so, if the tensioner is weak, jammed, noisy or badly corroded, replace it.

When changing a timing belt on an overhead cam engine, the pulleys should be inspected for alignment and wear. Belt tension must be set to manufacturer specifications.

BELT MAINTENANCE

Belt manufacturers say the incidence of normal V-belt failure rises sharply after three years of service, and four years with serpentine belts. Hose manufacturers say hose failures go up after four years of service. The average passenger car or light truck typically racks up 60,000 to 70,000 miles in four years, so any vehicle that is more than four years old is a potential candidate for belt and hose replacement.

But what happens if never replace your belts or hoses? Hopefully nothing because nobody can predict when a belt or hose will actually fail. But if a failure does occur, the consequences can often be far more serious and expensive than a breakdown and a tow. Overheating is the biggest danger. Depending on how hot an engine gets, the consequences may include a blown head gasket, a cracked or warped cylinder head and/or broken or frozen overhead camshaft.

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Water Pump Diagnosis & Replacement

By Larry Carley c2007

The water pump is the heart of the cooling system. The pump circulates coolant between the engine and radiator to keep the engine from overheating. Inside the pump is a metal or plastic impeller with blades that push the water through the pump. The impeller is mounted on a shaft that is supported by the pump housing with a bearing and seal assembly. The water pump is usually belt driven and is mounted on the front of the engine.

WATER PUMP PROBLEMS

Water pumps typically fail one of two ways: the shaft seal starts to leak, or the impeller inside breaks, comes loose or the blades erode and wear down (which is more of a problem with pumps that have plastic impellers).

When a water pump starts to leak, the cooling system will lose coolant. If the leak is not discovered, the loss of coolant will eventually cause the engine to overheat. The drive may not realize anything is wrong until the temperature warning light comes on. If this happens to you, shut the engine off immediately. Severe engine damage can result if an overheating engine is driven too far.

If the engine has overheated, the entire cooling system (radiator, hoses, water pump and engine) must all be inspected to see if there are any coolant leaks. If coolant is leaking out of the water pump shaft or vent hole, the water pump needs to be replaced. Cooling system sealer cannot stop this kind of leak.

WATER PUMP SEAL FAILURE

A seal on the water pump shaft prevents coolant from leaking past the bearing. Seal wear can be caused by rust, sediment or other contaminants that are circulating with the coolant inside the cooling system. The pump shaft and bearings are also under constant load not only from the drive belt or timing belt but also the fan on vehicles with pump-mounted mechanical cooling fans. Eventually the water pump shaft seal and/or bearing wears out and the pump begins to leak.

Most OEM water pumps are designed to go 100,000 miles or more, but they don't always go the distance. It's not unusual to see leaks occur after 50,000 or 60,000 miles. If the pump shaft shows any visible wobble or the bearings are making noise, the pump should be replaced even if it isn't leaking (because it soon will be!).

WATER PUMP FAILURES

Sometimes a water pump will fail internally due to severe corrosion wearing away the impeller blades, or the impeller comes loose on the shaft, or the shaft itself may break from metal fatigue (caused by flexing due to an out-of-balance fan).

Many late model vehicles (Chrysler in particular) have plastic impellers to improve cooling efficiency and to reduce cavitation (drag). But the plastic can wear down quickly if the coolant is dirty and contains abrasives. The pump may not leak, but it may not circulate enough coolant through the engine to keep the engine at normal operating temperature.

One way to test for a bad water pump is to squeeze the upper radiator hose when the engine is hot and idling. Careful, because teh hose willb e HOT! If you do not feel much coolant circulating through the hose when you rev the engine, the pump may be bad. The other cause might be a bad thermostat that is not opening properly (remove and inspect the thermostat), or a clogged radiator.

REPLACING A WATER PUMP

Replacement water pumps come in a wide variety of shapes and sizes as well as shaft lengths, and on some engines more than one style of pump may be used. Finding the right pump means matching not only the year, make, model and engine, but sometimes also the VIN or casting number. If possible, compare the replacement pump to the old pump to make sure it is the right one for the application. To consolidate applications, some replacement castings have extra outlets and mounting bosses or bolt holes so it can be used on a wider variety of engine applications. That's okay as long as there are enough outlets and mounting bosses to match the original casting.

Removing the old pump typically involves the following steps:

1. Drain the radiator. Open the petcock valve at the bottom of the radiator, or if there is no drain valve, loosen the lower radiator hose. Do this when the engine is COLD. Catch the coolant in a bucket for reuse later, or safe disposal if it is time to change the coolant. Use antifreeze can usually be flushed down the toilet. DO NOT dump it into a storm sewer or on the ground because it is toxic and will kill plants. It is also poisonous to animals and people.

2. Remove the fan belt. On engines with a serpentine belt drive, this means loosening the tension on the automatic tensioner. Note how the belt is routed BEFORE you remove it so you can reinstall it later correctly (draw a picture if there is not a belt decal under the hood that shows how the belt is routed around the pulleys).

3. Remove anything else that is the way. This may include the fan, fan shroud, timing belt cover if the pump is driven off the timing belt on an OHC engine instead of a serpentine belt, or any brackets or other engine-mounted accessories that are blocking access to the pump.

4. Unbolt the water pump from the engine.

5. Clean the pump mounting surface to remove all traces of old gaskets. The mounting surface must be clean and dry befoe you install the new pump.

6. Position the gasket on the new pump, using gasket sealer or adhesive as required, then bolt the new water pump to the engine. Use thread sealer on any threads that screw all the way through into open water jackets (not needed with blind bolt holes).

7.Refill the cooling system. Be patient because it may take some time for all the air to vent out. Many cooling systems have vent valves that can be opened during a refill to allow air a place to escape.

Notes:

If the cooling system contains rust or sediment, the radiator and block should be cleaned and flushed BEFORE you remove the old pump to protect the new pump from possible damage.

If the coolant that you drained out of the radiator is rusty or dirty, do not reuse it. Refill the cooling system with a 50/50 mixture of new antifreeze and clean, distilled water. Do not use tap water or softened water because it contains minerals and salts that can cause corrosion inside the cooling system.

If the vehicle has a pump-mounted mechanical fan with a fan clutch, the fan clutch should also be replaced at the same time. The service life of the fan clutch is about the same as the pump. A slipping fan clutch will reduce radiator cooling and may cause the engine to overheat.

Other parts that may be needed to complete the job include a new thermostat (recommended if the engine overheated), new radiator and heater hoses (hoses that are cracked, brittle or unusually soft should be replaced), and new hose clamps.

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How To Find & Fix Coolant Leaks

By Larry Carley, c2007

Coolant leaks rarely pass unnoticed for long because sooner or later the engine will overheat from the loss of coolant. So if you are driving a leaker, keep reading because we're about to tell you how to find and fix your coolant leak.

WHERE COOLANT LEAKS OCCUR

Coolant leaks can occur anywhere in the cooling system. Nine out of ten times, coolant leaks are easy to find because the coolant can be seen dripping, spraying, seeping or bubbling from the leaky component. So open the hood and visually inspect the engine and cooling system for any sign of liquid leaking from the engine, radiator or hoses. The color of the coolant may be green, orange or yellow depending on the type of antifreeze in the system. The most common places where coolant may be leaking are:
a bad water pump shaft seal can leak coolant A worn seal on the water pump shaft can leak coolant.

Water pump. A bead shaft seal will allow coolant to dribble out of the vent hole just under the water pump pulley shaft. If the water pump is a two-piece unit with a backing plate, the gasket between the housing and back cover may be leaking. The gasket or o-ring that seals the pump to the engine front cover on cover-mounted water pumps can also leak coolant. Look for stains, discoloration or liquid coolant on the outside of the water pump or engine.
radiator corrosion This radiator is badly corroded and is not worth fixing

Radiator. Radiators can develop leaks around upper or loser hose connections as a result of vibration. The seams where the core is mated to the end tanks is another place where leaks frequently develop, as is the area where the cooling tubes in the core are connected or soldered to the core headers. The core itself is also vulnerable to stone damage. But a major factor in many radiator leaks is internal corrosion that eats away from the inside out. That's why regular coolant flushes and replacing the antifreeze is so important.

Most cooling systems today are designed to operate at 8 to 14 psi, so if the radiator can't hold pressure your engine will overheat and lose coolant.
radiator hose can leak coolant Pinch hoses to check for age cracks, hardening, soft spots, blisters or bulges.

Hoses. Cracks, pinholes or splits in a radiator hose or heater hose will leak coolant. A hose leak will usually send a stream of hot coolant spraying out of the hose. A corroded hose connection or a loose or damaged hose clamp may also allow coolant to leak from the end of a hose. Sometimes the leak may only occur once the hose gets hot and the pinhole or crack opens up.

Freeze plugs (casting plugs or expansion plugs in the sides of the engine block and/or cylinder head). The flat steel plugs corroded from the inside out, and eventually eat through allowing coolant to leak from the engine. The plugs may be hard to see because they are behind the exhaust manifold, engine mount or other engine accessories. On V6 and V8 blocks, the plugs are most easily inspected from underneath the vehicle.

Heater Core. The heater core is located inside the heating ventilation and air conditioning (HVAC) unit under the dash. It is out of sight so you can’t see a leak directly. But if the heater core is leaking (or a hose connection to the heater core is leaking), coolant will be seeping out of the bottom of the HVAC unit and dripping on the carpet. Look for stains or wet spots on the bottom of the plastic HVAC case, or on the passenger side floor.

Intake Manifold gasket. The gasket that seals the intake manifold to the cylinder heads may leak and allow coolant to enter the intake port, crankcase or dribble down the outside of the engine. Some engines such as General Motors 3.1L and 3.4L V6 engines as well as 4.3L, 5.0L and 5.7L V8s are notorious for leaky intake manifold gaskets. The intake manifold gaskets on these engines are plastic and often fail at 30,000 to 80,000 miles. Other troublesome applications include the intake manifold gaskets on Buick 3800 V6 and Ford 4.0L V6 engines.

INTERNAL COOLANT LEAKS

There are the worst kind of coolant leaks for two reasons. One is that they are impossible to see because they are hidden inside the engine. The other is that internal coolant leaks can be very expensive to repair.
a bad head gasket can leak coolant

Bad head gasket. Internal coolant leaks are most often due to a bad head gasket. The head gasket may leak coolant into a cylinder, or into the crankcase. Coolant leaks into the crankcase dilute the oil and can damage the engine’s bearings. The repair involves removing the cylinder head to replace the gasket (typically a $1000 to $1500 repair job).

If you suspect a head gasket leak, the engine should be given a compression test. A low reading in a cylinder (or two adjacent cylinders) means the gasket is not sealing the cylinder(s). Low compression will also cause a noticeable loss of power and/or a miss.

Head gasket failures are often the result of engine overheating (which may have occurred because of a coolant leak elsewhere in the cooling system, a bad thermostat, or an electric cooling fan not working). When the engine overheats, thermal expansion can crush and damage portions of the head gasket. This damaged areas may then start to leak combustion pressure and/or coolant.

Cracked Head or Block. Internal coolant leaks can also occur if the cylinder head or engine block has a crack in a cooling jacket. A combustion chamber leak in the cylinder head or block will leak coolant into the cylinder. This dilutes the oil on the cylinder walls and can damage the piston and rings. If the coolant contains silicates (conventional green antifreeze), it can also foul the oxygen sensor and catalytic converter. If enough coolant leaks into the cylinder (as when the engine is sitting overnight), it may even hydro-lock the engine and prevent it from cranking when you try to start it.

A coolant leak into the crankcase is also bad news because it can damage the bearings. Coolant leaking into the crankcase will make the oil level on the dipstick appear to be higher than normal. The oil may also appear frothy, muddy or discolored because of the coolant contamination.

Leaky ATF oil cooler. Internal coolant leakage can also occur in the automatic transmission fluid oil cooler inside the radiator. On most vehicles with automatic transmissions, ATF is routed through an oil cooler inside the radiator. If the tubing leaks, coolant can enter the transmission lines, contaminate the fluid and ruin the transmission. Red or brown drops of oil in the coolant would be a symptom of such a leak. Because the oil cooler is inside the radiator, the radiator must be replaced to eliminate the problem. The transmission fluid should also be changed.

PRESSURE TESTING THE COOLING SYSTEM

There are several ways to find out whether or not your cooling system is holding pressure. One is to top off your cooling system, tighten the radiator cap and start the engine. When the engine reaches normal operating temperature, turn on the air conditioner (to increase the cooling load on the system) and/or take it for a short drive. Then check the radiator, hoses and water pump for seepage or leaks.

WARNING: DO NOT open the radiator cap while the engine is hot! Even if the cooling system is leaking, the coolant will be under considerable pressure -- especially if it is low and coolant is boiling inside the engine. Shut the engine off and let it sit about an hour so it can cool down. Then place a rag over the radiator cap and slowly turn the cap until it starts to release pressure. Wait until all the pressure has vented before turning the cap the rest of the way off.

A special tool called a pressure tester can also be used to check your cooling system. The tool is nothing more than a little hand pump with a combination vacuum-pressure gauge and a fitting that is attached to the radiator filler neck. To check for leaks, attach the tool to the radiator and pressurize the radiator to the pressure rating on the radiator cap. For example, if you have a radiator cap that says 12 pounds, you pressurize the radiator to 12 lbs. and wait to see what happens. If there are no leaks, the system should hold pressure for 10 to 15 minutes. If it doesn’t hold pressure, the system is leaking. If you cannot see any visible leaks on the outside, it means the leak is inside (bad head gasket or cracked head or block).

Leak detection dye can also be added to the coolant to make a slow leak easier to find. Some of these dyes glow bright green or yellow when exposed to ultraviolet light.

RADIATOR CAP CHECKS

It's also important to pressure check the radiator cap, especially if the system has been overheating or losing coolant with no obvious external leaks. A weak cap that can't hold pressure will allow the system to boil over. If the cap can't hold its rated pressure, replace it.
replace radiator to repair coolant leak The best fox for a leaky radiator is to replace it with a new or recored radiator.

RADIATOR REPAIRS

If your radiator is leaking, you have several repair options:

You can try the cheap fix and add a bottle of cooling system sealer to the radiator. These products are designed to seal small leaks. They can also seal internal engine leaks. Some work better than others, but most provide only a temporary solution to your problem.

You can attempt to repair the radiator yourself. Copper/brass radiators on older vehicles can often be soldered to repair leaks. Cracks or pinholes in aluminum radiators in newer vehicles can often be repaired with epoxy glue. But if the core is severely corroded or damaged, the radiator may have to be professionally repaired at a radiator shop, or replaced with a new radiator.

FIXING A LEAKY HEATER CORE

As with a leaky radiator, you might try the cheap fix and add a bottle of cooling system sealer to see if that will stop the leak. If it does not, you will have to disassemble the HVAC case to replace the heater core. This is a nasty job and involves a LOT of labor on most vehicles.

If a vehicle has a history of repeat heater core failures (some Chrysler cars, for example), the problem may be electrolysis corroding the heater core. One fix is to attach a grounding strap on the heater core. Another is to replace the OEM aluminum heater core with an aftermarket copper/brass heater core.

COOLANT RESERVOIR

Another coolant component that sometimes needs attention is the coolant overflow reservoir. The coolant overflow reservoir does more than catch the overflow from the radiator. It's main function is to serves as a storage tank for excess coolant. When the system is hot, coolant will be forced out through the radiator pressure cap and into the reservoir. Then as the system cools down, decreasing pressure will draw coolant back into the radiator.

On many newer vehicles, the coolant reservoir is pressurized and is an integral part of the cooling system. The filler cap for the cooling system is located on the reservoir tank, and the tank is connected to the radiator and engine with hoses. The reservoir is transparent plastic and you can see the coolant level inside.

If the coolant reservoir is cracked or leaking, the system may lose coolant every time the engine heats up. Eventually, this can cause the engine to overheat.

Small punctures or cracks in the overflow reservoir can usually be repaired with silicone glue. If the reservoir needs to be replaced, make sure the hoses are routed correctly between the radiator and the reservoir, and that it is free from kinks that could block the flow of coolant back and forth.

FIXING LEAKY FREEZE PLUG

There are several ways to repair a leaky freeze plug.

One is to clean the surface of the plug, then sand it lightly with sandpaper, and pack it solid with a high temperature two-part epoxy such as gas tank sealer. Let it cure overnight. This trick usually seals leaky expansion plugs that would otherwise be very difficult to replace.

Another is to use a hammer and drift to knock out the old plug. Pounding in on one side of the plug will usually cause it to twist. The plug can then be pried out with a large screwdriver. Clean the hole, then apply a liberal coating of sealer to the hole and carefully drive in a new replacement plug. The plug must go in straight or it may not seal. Another option is to install a repair plug that has an expandable rubber grommet to seal the hole. You simply place the plug in the hole and tighten the bolt until it seals tight.

FIXING LEAKY HOSES

Do not waste your time trying to patch or wrap a leaky radiator or heater hose. Sealers do not work well with hoses either. Replace the bad hose with a new one, and inspect all the other hoses because if one has failed the others are probably reaching the end of the road, too. It is also a good idea to replace the original hose clamps, especially if they are the ring type. Ring clamps can lose tension with age and may not hold the hose tightly. Worm drive clamps are recommended.

FIXING A LEAKY WATER PUMP

No stop leak will seal a water pump that's losing coolant past the shaft seal. Replacement is your only option here. But you can save some money on the job by using a remanufactured rather than a new pump.

Replacing a water pump is not too hard a job on most engines, but on some it can be tricky. On 2.8L GM V6 engines, for example, the bolts that hold the water pump also hold the timing cover in place. If you are not careful, the timing cover seal can be broken allowing coolant to leak into the crankcase. GM recommends using a special tool (J-29176 or equivalent) to hold the timing cover tight while the pump is being changed.
fan clutch Check the fan clutch because a weak clutch can cause the engine to overheat.

If your engine has a belt-driven fan with a fan clutch, it is also a good idea to check the fan clutch when replacing the water pump. The lifespan of both is about the same, so the fan clutch may also need be replaced. If the clutch is leaking silicone fluid, or has any wobble in the bearing, it must be replaced.

REFILLING THE COOLING SYSTEM

When refilling the cooling system after making a repair, always use a 50/50 mixture of antifreeze and water. Never use straight water because it has no freezing protection, no corrosion protection and it boils at a lower temperature (212 degrees F.) than a mixture of antifreeze and water (which protects to 240 degrees F.).

On some late model front-wheel drive cars, refilling the cooling system can be tricky unless you "burp" the system by opening a bleeder vent or cracking a hose at a high point in the system to allow trapped air to escape. If you do not get all of the air out, the engine may overheat the first time you drive it.

The best way to refill the system is to add coolant until the radiator is within an inch of being full. Also add coolant to the coolant reservoir, filling it to the proper level. If the system has a pressurized coolant reservoir, add coolant until the level inside the reservoir is at the COLD FULL mark. Start the engine and let it idle with the radiator or coolant reservoir cap off until the thermostat opens and coolant starts to circulate through the engine. The heater should also be on so coolant will flow through the heater core. As the coolant level drops, continue to add coolant until the system takes no more. Then replace the radiator cap and drive a short distance. Shut the engine off, and after it has cooled recheck the coolant level once again. If low, add as needed.

Link

 

Diagnosis: Engine Won't Start or Run

by Larry Carley c2007

WHEN AN ENGINE WON'T START

Every engine requires four basic ingredients to start: sufficient cranking speed, good compression, adequate ignition voltage (with correct timing) and fuel (a relatively rich air/fuel mixture initially). So any time an engine fails to start, you can assume it lacks one of these four essential ingredients. But which one?

To find you, you need to analyze the situation. If the engine won't crank, you are probably dealing with a starter or battery problem. Has the starter been acting up? (unusual noises, slow cranking, etc.). Is this the first time the engine has failed to crank or start, or has it happened before? Have the starter, battery or battery cables been replaced recently? Might be a defective part. Has the battery been running down? Might be a charging problem. Have there been any other electrical problems? The answers to these questions should shed some light on what might be causing the problem.

If an engine cranks but refuses to start, it lacks ignition, fuel or compression. Was it running fine but quit suddenly? The most likely causes here would be a failed fuel pump, ignition module or broken overhead cam timing belt. Has the engine been getting progressively harder to start? If yes, consider the engine's maintenance and repair history.

STARTING YOUR DIAGNOSIS

What happens when you attempt to start the engine? If nothing happens when you turn the key, check the battery to determine its state of charge. Many starters won't do a thing unless there is at least 10 volts available from the battery. A low battery does not necessarily mean the battery is the problem, though. The battery may have been run down by prolonged cranking while trying to start the engine. Or, the battery's low state of charge may be the result of a charging system problem. Either way, the battery needs to be recharged and tested.

If the battery is low, the next logical step might be to try starting the engine with another battery or a charger. If the engine cranks normally and roars to life, you can assume the problem was a dead battery, or a charging problem that allowed the battery to run down. If the battery accepts a charge and tests okay, checking the output of the charging system should help you identify any problems there.

A charging system that is working properly should produce a charging voltage of somewhere around 14 volts at idle with the lights and accessories off. When the engine is first started, the charging voltage should rise quickly to about two volts above base battery voltage, then taper off, leveling out at the specified voltage. The exact charging voltage will vary according to the battery's state of charge, the load on the electrical system, and temperature. The lower the temperature, the higher the charging voltage. The higher the temperature, the lower the charging voltage. The charging range for a typical alternator might be 13.9 to 14.4 volts at 80 degrees F, but increase to 14.9 to 15.8 volts at subzero temperatures.

If the charging system is not putting out the required voltage, is it the alternator or the regulator? Full fielding the alternator to bypass the regulator should tell you if it is working correctly. Or, take the alternator to a parts store and have it bench tested. If the charging voltage goes up when the regulator is bypassed, the problem is the regulator (or the engine computer in the case of computer-regulated systems). If there is no change in output voltage, the alternator is the culprit.

Many times one or more diodes in the alternator rectifier assembly will have failed, causing a drop in the unit's output. The alternator will still produce current, but not enough to keep the battery fully charged. This type of failure will show up on an oscilloscope as one or more missing humps in the alternator waveform. Most charging system analyzers can detect this type of problem.
typical starter circuit

ENGINE CRANKING PROBLEMS

If the engine won't crank or cranks slowly when you attempt to start or jump start the engine (and the battery is fully charged), you can focus your attention on the starter circuit. A quick way to diagnose cranking problems is to switch on the headlights and watch what happens when you attempt to start the engine. If the headlights go out, a poor battery cable connection may be strangling the flow of amps. All battery cable connections should be checked and cleaned along with the engine-to-chassis ground straps.

Measuring the voltage dropacross connections is a good way to find excessive resistance. A voltmeter check of the cable connections should show no more than 0.1 volt drop at any point, and no more than 0.4 volts for the entire starter circuit. A higher voltage drop would indicate excessive resistance and a need for cleaning or tightening.

Slow cranking can also be caused by undersized battery cables. Some cheap replacement cables have small gauge wire encased in thick insulation. The cables look the same size as the originals on the outside, but inside there is not enough wire to handle the amps.

If the headlights continue to shine brightly when you attempt to start the engine and nothing happens (no cranking), voltage is not reaching the starter. The problem here is likely an open or misadjusted park/neutral safety switch, a bad ignition switch, or a faulty starter relay or solenoid. Fuses and fusible links should also be checked because overloads caused by continuous cranking or jump starting may have blown one of these protective devices.

If the starter or solenoid clicks but nothing else happens when you attempt to start the engine, there may not be enough amps to spin the starter. Or the starter may be bad. A poor battery cable, solenoid or ground connection, or high resistance in the solenoid itself may be the problem. A voltage check at the solenoid will reveal if battery voltage is passing through the ignition switch circuit. If the solenoid or relay is receiving battery voltage but is not closing or passing enough amps from the battery to spin the starter motor, the solenoid ground may be bad or the contacts in the solenoid may be worn, pitted or corroded. If the starter cranks when the solenoid is bypassed, a new solenoid is needed, not a starter.

Most engines need a cranking speed of 200 to 300 rpm to start, so if the starter is weak and can't crank the engine fast enough to build compression, the engine won't start. In some instances, a weak starter may crank the engine fast enough but prevent it from starting because it draws all the power from the battery and does not leave enough for the injectors or ignition system.

If the lights dim and there is little or no cranking when you attempt to start the engine, the starter may be locked up, dragging or suffering from high internal resistance, worn brushes, shorts or opens in the windings or armature. A starter current draw test will tell you if the starter is pulling too many amps.

A good starter will normally draw 60 to 150 amps with no load on it, and up to 200 amps or more while cranking the engine. The no load amp draw depends on the rating of the starter while the cranking amp draw depends on the displacement and compression of the engine. Always refer to the OEM specs for the exact amp values. Some "high torque" GM starters, for example, may have a no load draw of up to 250 amps. Toyota starters on four-cylinder engines typically draw 130 to 150 amps, and up to 175 amps on six-cylinder engines.

An unusually high current draw and low free turning speed or cranking speed typically indicates a shorted armature, grounded armature or field coils, or excessive friction within the starter itself (dirty, worn or binding bearings or bushings, a bent armature shaft or contact between the armature and field coils). The magnets in permanent magnet starters can sometimes break or separate from the housing and drag against the armature.

A starter that does not turn at all and draws a high current may have a ground in the terminal or field coils, or a frozen armature. On the other hand, the start may be fine but can't crank the engine because the engine is seized or hydrolocked. So before you condemn the starter, try turning the engine over by hand. Won't budge? Then the engine is probably locked up.

A starter that won't spin at all and draws zero amps has an open field circuit, open armature coils, defective brushes or a defective solenoid. Low free turning speed combined with a low current draw indicates high internal resistance (bad connections, bad brushes, open field coils or armature windings).

If the starter motor spins but fails to engage the flywheel, the cause may be a weak solenoid, defective starter drive or broken teeth on the flywheel. A starter drive that is on the verge of failure may engage briefly but then slip. Pull the starter and inspect the drive. It should turn freely in one direction but not in the other. A bad drive will turn freely in both directions or not at all.

ENGINE CRANKS BUT WILL NOT START

When the engine cranks normally but won't start, you need to check ignition, fuel and compression. Ignition is easy enough to check with a spark tester or by positioning a plug wire near a good ground. No spark? The most likely causes would be a failed ignition module, distributor pickup or Hall effect crankshaft position sensor.

A tool such as an Ignition System Simulator can speed the diagnosis by quickly telling you if the ignition module and coil are capable of producing a spark with a simulated timing input signal. If the simulated signal generates a spark, the problem is a bad distributor pickup or crankshaft position sensor. No spark would point to a bad module or coil. Measuring ignition coil primary and secondary resistance can rule out that component as the culprit.

Module problems as well as pickup problems are often caused by loose, broken or corroded wiring terminals and connectors. Older GM HEI ignition modules are notorious for this. If you are working on a distributorless ignition system with a Hall effect crankshaft position sensor, check the sensor's reference voltage (VRef) and ground. The sensor must have 5 volts or it will remain permanently off and not generate a crank signal (which should set a fault code). Measure VRef between the sensor power supply wire and ground (use the engine block for a ground, not the sensor ground circuit wire). Don't see 5 volts? Then check the sensor wiring harness for loose or corroded connectors. A poor ground connection will have the same effect on the sensor operation as a bad VRef supply. Measure the voltage drop between the sensor ground wire and the engine block. More than a 0.1 voltage drop indicates a bad ground connection. Check the sensor mounting and wiring harness.

If a Hall effect crank sensor has power and ground, the next thing to check would be its output. With nothing in the sensor window, the sensor should be "on" and read 5 volts (VRef). Measure the sensor D.C. output voltage between the sensor signal output wire and ground (use the engine block again, not the ground wire). When the engine is cranked, the sensor output should drop to zero every time the shutter blade, notch, magnetic button or gear tooth passes through the sensor. No change in voltage would indicate a bad sensor that needs to be replaced.

If the primary side of the ignition system seems to be producing a trigger signal for the coil but the voltage is not reaching the plugs, a visual inspection of the coil tower, distributor cap, rotor and plug wires should be made to identify any defects that might be preventing the spark from reaching its intended destination.

ENGINE CRANKS AND HAS SPARK BUT WILL NOT START

If you see a good hot spark when you crank the engine, but it won't start, check for fuel. The problem might be a bad fuel pump.

On an older engine with a carburetor, pump the throttle linkage and look for fuel squirting into the carburetor throat. No fuel? Possible causes include a bad mechanical fuel pump, stuck needle valve in the carburetor, a plugged fuel line or fuel filter.

On newer vehicles with electronic fuel injection, connect a pressure gauge to the fuel rail to see if there is any pressure in the line. No pressure when the key is on? Check for a failed fuel pump, pump relay, fuse or wiring problem. On Fords, don't forget to check the inertia safety switch which is usually hidden in the trunk or under a rear kick panel. The switch shuts off the fuel pump in an accident. So if the switch has been tripped, resetting it should restore the flow of fuel to the engine. Lack of fuel can also be caused by obstructions in the fuel line or pickup sock inside the tank. And don't forget to check the fuel gauge. It is amazing how many no starts are caused by an empty fuel tank.

There is also the possibility that the fuel in the tank may be heavily contaminated with water or overloaded with alcohol. If the tank was just filled, bad gas might be causing the problem.

On EFI-equipped engines, fuel pressure in the line does not necessarily mean the fuel is being injected into the engine. Listen for clicking or buzzing that would indicate the injectors are working. No noise? Check for voltage and ground at the injectors. A defective ECM may not be driving the injectors, or the EFI power supply relay may have called it quits. Some EFI-systems rely on input from the camshaft position sensor to generate the injector pulses. Loss of this signal could prevent the system from functioning.

Even if there is fuel and it is being delivered to the engine, a massive vacuum leak could be preventing the engine from starting. A large enough vacuum leak will lean out the air/fuel ratio to such an extent that the mixture won't ignite. An EGR valve that is stuck wide open, a disconnected PCV hose, loose vacuum hose for the power brake booster, or similar leak could be the culprit. Check all vacuum connections and listen for unusual sucking noises while cranking.

ENGINE HAS FUEL AND SPARK BUT WILL NOT START

An engine that has fuel and spark, no serious vacuum leaks and cranks normally should start. The problem is compression . If it is an overhead cam engine with a rubber timing belt, a broken timing belt would be the most likely cause especially if the engine has a lot of miles on it. Most OEMs recommend replacing the OHC timing belt every 60,000 miles for preventative maintenance, but many belts are never changed. Eventually they break, and when they do the engine stops dead in its tracks. And in engines that lack sufficient valve-to-piston clearance as many import engines and some domestic engines do, it also causes extensive damage (bent valves and valvetrain components & sometimes cracked pistons).

Overhead cams can also bind and break if the head warps due to severe overheating, or the cam bearings are starved for lubrication. A cam seizure may occur during a subzero cold start if the oil in the crankcase is too thick and is slow to reach the cam (a good reason for using 5W-20 or 5W-30 for winter driving). High rpm cam failure can occur if the oil level is low or the oil is long overdue for a change.

With high mileage pushrod engines, the timing chain may have broken or slipped. Either type of problem can be diagnosed by doing a compression check and/or removing a valve cover and watching for valve movement when the engine is cranked.

A blown head gasket may prevent an engine from starting if the engine is a four cylinder with two dead cylinders. But most six or eight cylinder engines will sputter to life and run roughly even with a blown gasket. The gasket can, however, allow coolant to leak into the cylinder and hydrolock the engine.

Link

 

Auto Repair Safety Tips

By Larry Carley c2007

Doing your own auto repair work can save you money, but it can also be dirty, dangerous work.

The following tips are provided to help you avoid the dangers of auto repair so you don't injure yourself or someone else. Most of these tips are common sense warnings, but there may be some things you are not aware of that could pose a potential danger.

First and foremost, DO NOT attempt repairs that are beyond your ability. If you feel unsure about a repair, you should seek out a competent professional to do the work for you. Better to pay someone who knows what they are doing than to attempt to fix it yourself and screw it up. Many systems on vehicles today are very complex. Repairs often require considerable skill and expertise, not to mention special tools and equipment. A simple mistake could ruin sensitive (and expensive!) electronic components. So don't tackle jobs that are beyond your abilities.

Know your physical limits. Do NOT attempt repairs yourself if you are not physically able to do the work. Replacing certain components may require heavy lifting (changing or removing tires, pulling a cylinder head, etc.), crawling under the vehicle, laying or working in an awkward position, reaching, bending, twisting, pulling, tugging, straining, jerking and motions you may not be accustomed to making. Use common sense. If you have a bad back, joint problems or lack the physical strength to do something, then DIY auto repair is not for you. Hire someone to do it for you.

Be focused. DO NOT attempt to undertake any maintenance or repair work on your vehicle if you are tired, not feeling well, tipsy, intoxicated, on medication or otherwise impaired. Exhaustion, illness, alcoholic beverages and even some medications may affect your judgment and perception creating a potential for injury or error. Save the beer for after the job has been completed.

GENERAL AUTO REPAIR PRECAUTIONS

* Do NOT smoke when working on any fuel related components (fuel filter, carburetor, fuel injectors, fuel pump, fuel tank or fuel lines). Better yet, do NOT smoke at all. It is bad for your health!


* Have a fire extinguisher nearby just in case. The fire extinguisher should have a "B" (liquids & grease fires) and "C" (electrical fires) rating.


* Do NOT smoke or get any sparks near the battery. Batteries contain hydrogen gas which is very explosive. If jump starting a battery, make the final jumper connection to the engine or chassis.


* NEVER crawl under an improperly supported vehicle. In other words, never trust a jack alone to hold the vehicle up. Always use a pair of support stands positioned underneath the vehicle to keep it from falling on you. Make sure the weight ratings on the support stands is more than adequate to hold up the vehicle's weight, too. Do not use blocks of wood, boxes, wheels or bricks for supports because these may slip or collapse and allow the vehicle to fall.


* Always disconnect one of the battery cables or remove power fuses for a circuit when doing electrical repair work (as when replacing a starter, installing a radio, fixing a broken switch or wiring, etc.). This will prevent accidental shorts that could damage the wiring or start a fire. This is also a very important precaution to heed when working under the dash of any vehicle equipped with an air bag. Crossing the wrong wires might set off the air bag (which could cause injury and is very expensive to replace).


* Watch Out for the Air Bags!. If working on the steering column or under the instrument panel or dash, always disconnect the battery and wait at least 15 minutes before proceeding with any disassembly or wiring tests. Crossing, jumping or shorting wires in teh air bag circuit could cause the air bag(s) to accidentally deploy and possibly injure you.

* Never disconnect or unplug any electrical connector while the engine is running or the key is in the "on" position (unless you are specifically instructed to do so as part of a diagnostic procedure in a shop manual). Unplugging connectors while current is flowing through them creates a voltage spike that can damage sensitive and expensive electronic components.


* Do not wear loose clothing, jewelry, rings, neckties, scarves or bulky gloves when working on your vehicle. If you have long hair, tie it back or cover it. These items may become entangled in pulleys or moving parts causing serious injury, dismemberment or death!
* Watch out for moving parts such as drive belts, pulleys, fan and other moving parts when working under the hood if the engine is running. DO NOT lean over a mechanical cooling fan while revving the engine.


* Watch out for hot stuff. If the engine is running or the vehicle has been driven within the past half hour or so, the engine, radiator, exhaust manifolds, catalytic converter, muffler and pipes will be hot.


* NEVER open the radiator cap on a hot engine. Always allow the engine to cool for at least an hour before attempting to open the cap. Even then, use extreme caution. Place a rag over the cap, then loosen it slowly to the first detent or stop. At this point any residual pressure and steam should be released. Wait until all pressure has escaped before removing the cap the rest of the way.


* Avoid electrical shocks when working around the ignition system. The normal battery voltage in passenger car and light truck electrical systems is only 12 volts and will not harm you. But the ignition system bumps the primary voltage up to 25,000 to 40,000 volts which can give you a nasty shock if you touch a spark plug wire, the ignition coil or distributor cap while the engine is running.


* Wear eye protection when working under the vehicle (to keep dirt and debris from falling into your eyes), when pounding or grinding on anything (to keep metal chips out of your eyes), when jump starting the battery (to keep acid out of your eyes should the battery explode), when working on air conditioning components (to keep refrigerant out of your eyes), and/or when doing anything that might pose a risk to your sight.


* Wear ear protection when using loud pneumatic tools or when hammering, pounding, grinding, sawing, drilling, etc. Prolonged exposure to high levels of noise can cause permanent hearing loss.


* Wear breathing protection (an OSHA-approved mask, not just a cheap dust mask) when spray painting or using other chemicals that give off aromatic hydrocarbons. A dust mask is recommended when grinding, sanding or sand blasting. DO NOT use an air hose to blow brake dust off brake components. Brake dust may contain asbestos or other fibers that can cause lung disease if inhaled. Use a liquid cleaner to remove brake dust.


* Do not open any brake lines or replace any components in a vehicle equipped with an "integral" ABS system (one where the master cylinder is combined with the ABS modulator, pump and pressure accumulator) without first depressurizing the system. This can usually be done by depressing the brake pedal 24 to 40 times while the key is off.


* Use caution when opening any fuel lines on a fuel injected vehicle. The pressure in some systems may be as high as 80 to 90 psi when the engine is running. So do not open any fuel line while the engine is running unless your fire insurance and life insurance are both paid up. Residual fuel pressure can remain in the lines for many hours after the engine has been shut off. To minimize fuel spray, wrap a rag around the hose or line before loosening it, or relieve pressure in the line using a procedure approved by the vehicle manufacturer (refer to a shop manual for details).


* Minimize distractions while working on your vehicle. This includes small children, pets, friends, spouses, in-laws or others who may distract you from your work. This will go a long ways towards reducing the risk of injury and making a mistake.


* Tell someone if you are going to be working on your vehicle outdoors or if you are going to be working underneath your vehicle. Hopefully, they will know how to dial 911 should the need arise.


* Avoid shock hazards with extension cords & electrical tools. If you are working outdoors and using power tools, make sure the extension cord you are using is rated for outdoor use, that the extension cord and tools are properly grounded (a "ground fault interrupt" outlet is recommended), and that the cord has the proper amp rating for the tools you are using. DO NOT use an adapter plug to convert a three-prong grounded plug into a two prong plug.

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Car Won't Start?

by Larry Carley c2007

YOU TRY TO START TO START YOUR CAR AND IT WON'T START

What should you do when your car won't start? Diagnosing a no-start condition requires a logical approach to figuring out what might be preventing your car from starting. First, if the engine won't even crank over when you turn the ignition to START, your car obviously won't start.

When you turn the ignition key to start your car, voltage from the battery flows through the ignition switch to the Park/Neutral safety switch and/or brake pedal or clutch pedal safety switch (you have to push the pedal down before the circuit will complete) to the starter relay or solenoid. When the relay or solenoid is energized by voltage from the ignition switch circuit, it closes a contact that routes more power from the battery directly to the starter to crank the engine. The starter motor spins, pushes the starter drive gear to engage the flywheel and cranks the engine.
typical starter circuit

If the engine fails to crank, there is a fault in one of the components in the battery/ignition/starter circuit.

COMMON CAUSES OF NO-CRANK NO-START

Low battery (Check battery voltage, recharge if low, or jump start with another vehicle or battery charger).
Loose or corroded battery cables (Inspect, clean and tighten BOTH ends of BOTH battery cables).
Bad starter relay wiring connections or ground connection (Inspect, clean, tighten wiring connections).
Bad starter relay/solenoid (Check for voltage at relay, if relay has voltage but there is no "click" when key is turned to start, replace relay).
Bad starter (Jump battery voltage direct to starter to see if it spins, or remove starter and have it bench tested at auto parts store).
Damaged starter drive or teeth on flywheel (Remove starter and inspect drive gear and flywheel teeth, replace damaged parts if necessary).
Bad ignition switch (Check to see if voltage reaches starter relay/solenoid when turn to start. If not, check for open P/N switch and brake or clutch pedal switch. Replace ignition switch if defective).
Open P/N safety switch, or open Brake Pedal Safety Switch (automatic transmission) or open Clutch Pedal Switch (manual transmission). Bypass switch with jumper wire to see if engine cranks, or use test light or voltmeter to check for voltage passing through switch when ignition is turned to start.
Engine seized due to bearing failure or internal damage (Use socket and long handle to see if engine can be turned by hand, if not engine is locked up).
Engine hydrolocked due to coolant leak from leaky head gasket (Use socket and wrench to see if engine rotates, remove spark plugs and see if coolant comes out or engine can not be cranked with plugs out).

ENGINE CRANKS OKAY BUT WON'T START

If the engine cranks over normally when you attempt to start you car, but the engine does not start, the problem may be NO FUEL, NO SPARK or NO COMPRESSION. The engine needs adequate fuel pressure, a properly timed spark and normal compression to start.

TIP: To find why the engine won't start, remove the air inlet tube from the throttle body, push the throttle open and spray a small amount of aerosol starting fluid into the engine. Crank the engine. IF it has spark and compression but NO FUEL, it will start and run a few seconds before dying. If it does NOT start, it probably has NO SPARK.

TIP: Another method to check for spark is to pull a spark plug wire off of a spark plug (if it has plug wires, coil-on-plug ignitions do not) and place the open end of the plug wire near a metal surface on the engine. Have a helper crank the engine while you watch for a spark. DO NOT hold the wire while doing this as it can shock you. If you see a spark, the problem is not spark, but most likely NO FUEL or NO COMPRESSION. If you do not see a spark, the problem is in the IGNITION CIRCUIT.

TIP: Proper fuel pressure is critical for fuel injected engines to start and run. You should hear the fuel pump inside the fuel tank buzz for a couple of seconds when the ignition is turned on (no buzz means the pump is not running and the engine is not getting fuel). You can smell the tailpipe for gasoline vapors after cranking the engine. If you smell gas, the problem is likely not fuel but NO SPARK. You can also remove the plastic cap and press the schraeder valve test fitting on the fuel rail to see if there is any fuel pressure to the engine (not a very accurate test because fuel pressure must be at a certain level for the engine to start, for that you need a gauge). Even so, no fuel at the fuel rail would tell you fuel is not getting to the engine.

COMMON CAUSES OF NO FUEL

Bad fuel pump (Pump should run for a few seconds when ignition key is turned to start, no buzz means no fuel delivery to the engine).
Bad fuel pump relay (Relay is energized by PCM to route power to fuel pump when ignition is on).
Bad inertia fuel shut-off safety switch (Shuts off fuel in an accident, may have been tripped by a severe jolt, press button to reset).
Open in wiring anywhere in fuel pump wiring circuit (power or ground). Problem may be at wiring connector on top of fuel tank (hard to reach!).
No gas in fuel tank (Check the fuel gauge, and keep in mind the gauge may not be reading accurately).
Bad gas (Contaminated with water or too much alcohol or diesel fuel). If you just filled up with gas and now your car won't start, suspect bad gas.
Plugged Fuel Filter (When was the filter last changed?). Replace the filter. If plugged with rust,k fuel tank may also need to be cleaned or replaced.
Plugged or Pinched Fuel Line (Inspect fuel lines under vehicle for damage).
Leaky Fuel Pressure Regulator (Controls fuel pressure to injectors, which is critical for starting and proper air/fuel mixture).
No power to Fuel Injectors (Due to faulty fuel injector relay, blown fuse, no input signal to PCM from crank position sensor or cam position sensor, or bad PCM driver circuit). Injectors should usually have power when key is on. PCM grounds other side of injector circuit to pulse the injectors.
Major vacuum leak (An open EGR valve, disconnected vacuum hose, PCV valve, etc, can create a large vacuum leak and allow too much air to be sucked into the engine. This will make the air/fuel mixture too lean and make the engine hard to start. Engine will usually idle rough if it does start.
typical ignition circuit

COMMON CAUSES OF NO SPARK

Bad crankshaft position sensor or distributor pickup (Sends pulse signal to ignition module and/or PCM that is necessary to trigger the ignition coil(s)).
Bad ignition module (controls firing of ignition coil(s), may have an intermittent open in circuitry that causes loss of spark, hard starting or sudden stalling, usually when hot)
Bad ignition coil(s). Ignition coil creates high voltage to fire the spark plugs. On engines with a distributor, a bad coil will prevent spark at all the spark plugs. On engines with a distributorless ignition system or coil-on-plug ignition, a bad coil will only affect one or two cylinders depending on the application. This may make the engine hard to start, but it will run on the remaining cylinders that are firing.
Cracks or carbon tracks inside distributor cap or on rotor (allows spark to short to ground before it reaches the spark plugs).
Bad spark plug wires (if wet, cracked, burned or internal resistance exceeds specifications, can interfere with good spark and make engine hard to start).
Fouled spark plugs (if the electrodes are contaminated with deposits, spark may short to ground before jumping gap causing misfires. Can make engine hard to start and run poorly. If plugs are wet when removed, it means they are not firing or engine is flooded).

COMMON CAUSES OF NO COMPRESSION

Broken timing belt or chain (Belt failure will prevent the valves from opening. The engine will NOT run if the belt has broken, and it may have bent valves or other damage as a result of the belt breaking).
Broken camshaft (This can happen on an overhead cam engine if the engine has overheated, warped the head and seized the camshaft).
Plugged catalytic converter (Creates a restriction that causes exhaust backpressure to back up. Engine may start but usually dies within a minute or two).

DETAILED STEP-BY-STEP DIAGNOSTIC CHARTS & TEST SPECIFICATIONS

To accurately diagnose your vehicle, you will probably need wiring diagrams, detailed step-by-step diagnostic procedures and test specifications. To get this and other repair information for your car, use the links below:

Link

 

Do-It-Yourself Auto Repair Articles:

Auto Repair Safety Tips (READ THIS FIRST!)


Advice on How To Avoid Automotive Repair Fraud, Scams & Rip-Offs

A/C & Cooling System Problems

Basic Car Care, Lubrication & Maintenance


Brakes & Antilock Brake Systems (ABS)


CHECK ENGINE LIGHT & TROUBLE CODES

Common Car problems (by symptom)

Electrical, Starting & Charging System

Emission Controls

Engine Diagnosis, Repair & Rebuilding

Front-Wheel Drive (FWD)

Fuel System Problems


Preventive Maintenance Guidelines

Sensor & Powertrain Control Modules

Spark Plugs & Ignition Problems

Steering, Suspension, Alignment & Tires


Technical Service Bulletins & Recalls

Transmission related Troubles

Carley Library of Over 250 Automotive Diagnosis & Repair Articles -main library link

FAQ-AA1Car Quick Links Menu Information

 

No sense re-inventing the wheel when there are professionals out there that can explain things way better than I could. You could also check out the Discussion Forums out there related to the make of your vehicle. I check out a few related to Extreme 4x4ing, High Performance, Chevy and Jeep sites for my rigs.

 

Backcountry Repairs
"How to be prepared for a breakdown on the trail"

When going off highway you can never be totally prepared, or take everything you need to handle every breakdown situation. But if you take a few essentials on the trail, you can usually make repairs to get back home or at least back to camp.

If you have done your preventative maintenance right you won’t have to worry about belts or hoses going bad on the trial, but there are plenty of other things that can lead to breakdowns. Some of these are self-induced shock failures that overtax certain components past the breaking point. I will try to list the most common types of breakdowns and how to deal with them. This does not necessarily mean a permanent repair but a repair to get you home. I am going to list these breakdowns in an order that is only relative to my experience and nothing more. Everyone will have their own trail breakdown and repair stories. I have heard quite a few that are ingenious; from wooden pistons to bailing wire stitched up side walls. What you need is on the spot cleverness to deal with some problems, and with others an experienced mechanic. I will assume that you at least have a working knowledge of mechanical repairs.

If you don’t have much experience with repairs or even if you do, a smart item to carry with you is the service manual for your vehicle. A good mechanic always reads through the repair procedures before he starts a job he is not familiar with. Another thing that a service manual will tell you is if there are any special tools required. If there are, then these tools should be part of your tool kit. You would not need a special tool for a transmission or engine rebuild on the trail but if you need something special to pull a front half shaft, you had better have it with you. This isn’t to say that you need to fill the back of your vehicle with tools. I get by with just small tool sets and a few special tools that apply to the particular vehicle I am driving. For example, if you have a full size Ford or Chevy, you should carry an axle or spindle nut socket

There are lots of things that can cause mechanical failures on the trail. If you drive your vehicle regularly these things should show up when and where it is easier to deal with them than in the outback. If you have a "trail only" vehicle you should drive it on the road once in a while just to see if there are any problems. It is more common to see problems with trailered vehicles than with daily drivers.

Every situation is different so it would be impossible to list every possible cause and repair procedure for a breakdown. Here are some of the most common types, starting with tires.

Getting a flat tire is by far the most common type of breakdown. Always carry a good full-sized spare tire. You might want to pack a plug kit, but most of the tire problems I have seen are either not reparable, or simply a lost bead. One of the first essential items everyone that goes off highway needs to get is a good air compressor. Airing down to gain better traction is only outweighed by the increased ride quality. This will increase the odds of a lost tire bead however. Make sure your jack is in good working order. If you carry a High Lift Jack on the outside of your vehicle, check and oil it often. Another handy item for tire work is a nylon winch-type hold down strap. These can be put around the center of the tread and tightened to re-seat the bead. Never use starting fluid to re-seat the bead. This has lead to fatalities. It is a good idea to stand away from the tire when airing up. A sidewall can fail, causing what is known as a ‘zipper effect’. I prefer to carry a star wrench. It is easier to use to get lug nuts off and on than the lug wrench supplied with the vehicle.

The next most common problems, and some would argue the most common, are engine stalling problems. Other than a major internal mechanical failure, these can be divided into two types: fuel or electrical. Let’s start with fuel problems. Off camber situations are the norm when going off pavement. With a carbureted engine that was designed to operate mostly on the near level, off camber can cause flooding, or over-fueling, of the engine. This condition can also create a dangerous situation. Gas running out over the engine can lead to a fire under the hood. There is an easy fix for this; an adjustable fuel pressure regulator mounted at the inlet to the carburetor, set to 2 or 3 p.s.i. when off highway.

You can also lose fuel flow due to fuel pump failure or vapor lock. Some vehicles are more prone to vapor lock than others. Vapor lock is caused when the gasoline boils in the fuel line. This condition becomes more common with an increase of altitude. The temporary cure is to wait while things cool down. The permanent cure is to install an electrical fuel pump as close to the fuel tank as possible. If you have fuel pump problems, you might consider packing a spare electric fuel pump with your tool kit. Fuel injectioned engines are much more reliable However they need professional help to repair. Fuel injection also doesn’t care what angle you put it on.

The other thing that will cause an engine to stall is loss of the electrical system that fires the spark plugs. The older the vehicle, the easier the electrical system is to check out. The newer it is the more reliable it is. Other than getting wet, a basic understanding of the electrical system is needed for a proper diagnosis. A can of WD-40 should be in your tool kit, especially if stream fording is anticipated. If you stall after getting the outside of the engine wet, you will need to get rid of the moisture inside and outside the distributor cap, coil and the sparkplug wires. Spraying the WD-40 in these areas will dissipate the water. The use of silicone dielectric or tune up grease on the inside of the ends of the sparkplug wires and coil wire will effectively seal out moisture permanently. The only thing left to completely seal the secondary electrical system would be to seal the distributor cap.

The way to tell, when the engine stalls, if it is a fuel or an electrical problem is to pull a sparkplug wire off and turn the engine over to see if you have spark. You need to be careful when doing this as there are around 30,000 volts that can give you quite a shock. I will usually pull the wire off of a sparkplug and put a screwdriver into the end and lay it on the intake manifold so there is about 1/4" gap between the screwdriver and manifold. Have someone turn the engine over and watch for the spark. If you don’t have a good spark jump the gap then you can assume you have an electrical problem. If you get a good spark then chances are you need to look at the fuel system.

Next comes breakage due to over-taxing your vehicle. The weakest link in the drive train seems to be the U-joints. If you break a U-joint there is a good probability that you will damage the yoke as well. This usually is not a trail side repair. Just remember that you are diving a four-wheel drive vehicle and you can most often get home with either the front or rear drive disconnected. You will need to remove the drive shaft with the broken U-joint so that further damage is not done, then drive out in two wheel drive. If this is a front axle steering knuckle U-joint, the half shaft will need to be removed and a rag stuffed into the end of the open axle housing. If the drive shaft that needs to be removed has a slip yoke that splines into the back of the transmission, you will have to figure a way to keep the fluid in and the dirt out while getting where you can make permanent repairs.

Broken axles are also common. The type of vehicle you drive will determine if you need a ride to town to buy a new axle and replace it where you broke it, or simply remove it and drive off in two wheel drive. Full floating axles are the easiest to deal with. Simply unbolt both axles, push out the broken end, re-install the axles and drive home in two wheel drive. On the other hand, if the wheel is retained by a C-clip inside of the differential housing, then you will have to go to town for a new axle. There are many variations of axle retention so there is no way I could list all possible trail side repairs.

Engine fan contact with the radiator is another situation that I have seen on the trail. There are two ways in which this can happen. The first is during deep water crossings. The fan can be pulled into the radiator core when the fan blades are bent forward by un-compressible water. The other way is during a high torque or frame flexing maneuver like trying to make " Zukie Hill ". This type of repair will require you to pull the radiator. You will need to pull out, pinch off and solder the leaking tubes. As part of your kit you might consider a propane torch and acid core solder. This procedure does require a first hand knowledge of soldering. Modified vehicles are more at risk, due to body lifts and engine swaps, but I have seen this happen to new stock vehicles where the fan is close to the radiator.

Brake failure is something you want to repair before you go any further. One thing you never want to do is drive off pavement without a good parking brake. The usual reason for a brake failure is a leak. With modified vehicles it is usually due to brake lines having a hole rubbed into them from an overlooked body panel or too tightly stretched flex line. Older vehicles had only one brake system so if you developed a leak you would lose all the brakes. Newer vehicles have a front and rear brake system, so if you lose one system you will still have partial brakes. One way to deal with this on the trail is to pinch the leak off tightly with a pair of vise grip pliers, add brake fluid and bleed the brakes. Keep in mind that this will cause the vehicle to pull to one side. If you have to do this with a front brake it can almost pull the steering wheel out of your hands on a hard brake application. This would be only a very temporary repair but it would be better than no brakes at all. You would be better off going to town, buying a new brake line and repairing the brakes properly before going on.

There are certain precautions you should take before heading to the outback. Give some serious thought about what you would do if a major breakdown occurred. Could you deal with a major breakdown on a little used trail with no-one else around? This could lead to a life threatening situation you should have avoided in the first place. You should never go it alone on a remote, seldom used trail. This is one of the reasons 4X4 clubs are popular. Even if you don’t chose to join a club, trail ride events are scheduled most times of the year and everywhere in the country. There is security here, with all kinds of help if you have any problems. It is also the best way to gain off highway experience. If you do chose to go off alone, give yourself an out. Don’t go further than you can walk out and find help or shelter before dark. Carry food and water enough in case you have to spend the night with a broken down vehicle. Be prepared for an accident with first aid supplies and training on how to deal with injuries. Always let someone know where you are going and when you will be back.

I have come up with a list that, over the years, I have found useful when dealing with trail side repairs. If not completely obvious, there will be an explanation for each item listing my reason for including it. Some of the items I leave in the vehicles can come in handy at any time. It seems like alot, but it all fits in a couple of small cargo boxes behind the rear seat of my Amigo and in the Best Top Space Modules in our Wrangler. Recovery items go hand and hand with emergency repair items since some things do double duty.

Tool kit ( I carry a basic small kit that comes in its own case. If you think you need a Snap-On roll away and you have room, go for it.)
Electrical repair kit (test light, wire, an assortment of wire terminals and wire terminal pliers.)
Jumper cables
Air compressor and hose. ( I carry a small portable even though I have an on-board compressor in both vehicles.)
Bailing wire
Latex gloves ( these are great if you have to mess with a greasy U-joint and don’t have a good way to clean your hands along the trail. )
8’ X 10’ tarp ( This is so much better to lay on instead of the ground when working under the vehicle.)
Low and high pressure tire gauges.
Tire repair kit
3 or 4 quarts of engine oil ( You can use this in a pinch for rear end and manual transmission oil )
3 or 4 quarts of automatic transmission fluid ( for automatic transmissions only)
A pint of brake fluid
Engine oil filter and filter wrench ( I had a rock flip up and put a hole in one )
Cargo boxes that you can put all this stuff into
Hold down straps to secure the cargo boxes ( have at least one of these a winch type strap that can be used for re-seating a tire bead. )
Leather gloves ( For handling hot parts and winch cables )
Coveralls ( It is nice to be clean after the repairs are made )
Any special tools that are vehicle specific.
Any parts that seem to break often on your specific vehicle
Jack ( a high lift is very useful )
Tow strap ( Loop ends only, hooks turn into missiles )
Flashlight with extra batteries
Full size spare tire
Propane torch
Acid core solder
Roll of paper shop towels
Can of WD-40
Plastic garbage bag ( to cover large parts, doubles as rain slicker )
Zip lock bags ( to put small parts in )
Winch ( if you go it alone self recovery is very important )
Winch kit with tree saver, snatch block, clevis etc. ( if you have a winch )
This list is in no particular order of importance. I am sure that there are many other things you might want, or need, that is not on this list. If you find a need for something, make a note of it for the next trip. The next list is of items I take that I feel are needed when going off highway, not related to trail side repairs, but are important to have with me.

First aid kit ( Red Cross C.P.R. and Standard First Aid training should be considered if you spend much time out of doors )
Emergency survival kit ( at least extra food and water just in case you get stranded out on your own )
C.B. radio ( this is a must if you are going on any organized trail rides )
Maps of the area you are in and a compass
Sun screen
Bug repellent
Fire extinguisher
Extra clothing
Rain gear ( Ponchos don’t take up much room and they can double as small tarps )
Any prescriptions for medical problems
Here are some optional things I try to remember to take, but often forget.

G.P.S.
Cell phone
Cameras
Binoculars
Spotting telescope
Wife ( At least mine if I have her Jeep )
Anything else I have room for or I think I might need for that particular trip
This is not a very detailed report on trail side repairs. In future articles I hope to get into repair details on specific items. But for now I hope this will help. The easiest way to to be ready for a breakdown is to get familiar with your own vehicle by doing most, if not all, of the maintenance yourself.

Link

 

I had to break a window after locking the keys in the ignition on lunch break once

 

A lot of odd automotive stuff in TM-9-8000 File:TM 9-8000 PRINCIPLES OF AUTOMOTIVE VEHICLES.pdf - RadioNerds

I've had probably 50 cars, most of them beaters. In a real emergency situation there are some things I've done and seen that will get you there, but only in an emergency.

Rusted/broken brake line. It's not sending pressure anywhere and all your brake fluid is leaking out. You have no spare brake line, and you're running out of fluid. Cut the line off, bend the end that's coming from the master cylinder over and hammer it flat against the axle. It may still leak just a little, but it'll work. My brother drove a Ford Crown Victoria from Colorado to Michigan with no rear brakes, and the rear line crimped off like this.

Blown heater hose/leaking heater core. This one is easy if you're prepared. Just cut the hose on either side of the leak and install that piece of brass tubing and hose clamps you brought along. For a heater core, just loop the hoses together, and bypass the leaky heater core.

You can over a big hunk of rock and the transmission pan or oil pan has a pin hole leak. Screw a wood screw into it. This will seal it up until repairs can be made.

You drive a Ford. Carry extra coils, spark plugs, and silicone sealer.

Dead battery in one car, no jumper cables, MUST GO NOW! Remove top post battery from running car, invert charged battery and touch Pos (+) and Neg (-) terminals to dead top post battery. Start engine.
If you have a side post battery, start loading stuff in the running vehicle, or walk.

Diesel won't start, too cold, glow plugs don't work, no ether either. Remove junky plastic inlet tubing until you get to metal. Stuff or pile lightly wadded newspaper around inlet. Start the paper burning as you crank the engine. It'll suck flame into the intake, and hopefully heat up the cylinders enough to fire the engine off. You can spray anything flammable down the intake while the paper is there to ignite it, and it will help. Sure, you're sucking ash into the cylinders, and blasting the intake with orange model paint or Final Net hair spray. If it starts it beats walking, and diesels breathe carbon all the time. A little paper soot isn't going to bother them.
(Note: Ether as a starting fluid on smaller diesels WILL damage them. You might get lucky ccasionally, but most just can't handle the pressures of compression ignition on ether. I got three new engines in my HMMWV's in Norway from an impatient young Sergeant at the port with a can of ether. His maintenance unit wasn't pleased with having to do the extra work swapping engines in cramped bunker conditions. We enjoyed the refreshed vehicles.)

Tire puncture? Assorted size screws to plug the leak and get you where you're going. (Thanks Hanzo)

Serpentine belt broke? Even with a spare, lots of these are now stretchy belts with no tensioner and require a special tool to install them, often from underneath. Good to practice this ahead of time. Duct tape can make a questionable belt for a short trip, but it's better to have a spare.

Speaking of spares, where is yours? Flat? Buried in the trunk under all your gear, or hanging on the winch under the truck, and you have no experience getting it down from there? I had an experience like that. Had to drag bunches of stuff from trunk to the back seat to keep it secure as I dug for the spare tire. Now the spare and tools reside inside the left rear door. Immediate access, easy to maintain full pressure, and very limited exposure as I get it out and onto the car.

Vise grips, hose clamps, and wood screws can repair loose battery terminals.

Pipe plugs can seal up leaking oil pressure senders. You'll delete the sender to install the plug, but it won't leak.

Baseball bats and broom handles as a starting aid. Two applications here. Lightly on stubborn starter solenoids (or power window motors) that don't want to engage. Harder on the bottom of the fuel tank on GM trucks with failing fuel pumps. This will usually bump the worn out fuel pump motor into action.

Lots more little tips and tricks for beater drivers, but the most important piece of gear is always good shoes.

 

That silly folding or roll-up silver windshield sunshade that folks use in the Carolina's is the greatest thing going for getting under your car. Hot pavement or solid ice, you won't feel it through the insulated Mylar and styrafoam windsheld screen. the cutout for the mirror fits right around a tire when it's on the ground, and you can slide on it, or grab and edge and drag it along under you. The higher the quality the longer the service life. I use mine daily. Great piece of gear.

 

You got a MG too! I have a 1978 MGB and I'm hoping for a warm day soon so that I can take it for a spin... you know just to keep the battery charged and the wheels round.