Auto Repair Help
Reiner’s Corner – Auto Repair Help
DIAGNOSE – BURNING ODOR COMING FROM UNDER THE HOOD By Reiner B

Continued from Part 1

TIPS & TRICKS TO FIND AND FIX THE SOURCES OF BURNING ODORS

The odor of something burning under the hood is not only an inconvenience; it is also an unmistakable sign that something is seriously amiss with your car’s engine. If these types of issues are not resolved immediately, there is a high likelihood that that serious and even fatal damage to the engine can result, but worse, many engine fires are caused by oil and fluid leaks. Here is a quick rundown on the most common sites of fluid leaks, and what you can do to fix them-

OIL LEAKS

Oil leaks can occur almost anywhere on any engine at any time, but some leak sites are common to all engines. However, if oil leaks are left unresolved over long periods of time, the entire engine can eventually become covered with oil, which makes finding the site of a leak almost impossible. Therefore, it is recommended that the oil residue be cleaned off as much of the engine as possible before you attempt to trace an oil leak. However, if the engine is still reasonably free of oil deposits, things are considerably easier. Here is where to look for oil leaks-

NOTE: While evidence of oil and other fluid leaks are easy to see, finding the exact site of the leak can sometimes be very difficult, and sometimes impossible due to the design of modern engines and transmissions. One way to overcome the issue is to add a special dye to the engine, transmission, power steering system, A/C system, or cooling system that glows bright green when the dye escapes from the leak along with the fluid. The downside of these products is that they will only fluoresce under a UV light, but most major auto parts stores supply the dye and a UV light in a kit. Leak tracing dyes are an invaluable aid in tracing fluid leaks, and we strongly recommend that you treat the fluids in your vehicle with a dye product to make finding the sites of future fluid leaks easier.

Valve covers

While almost all manufacturers use rubber gaskets to seal the valve covers on their engines today, rubber gaskets harden and shrink over time. No amount of tightening bolts and or screws will resolve a leak past a degraded rubber gasket, and you will probably just damage screw threads in the cylinder head if you over tighten retaining bolts or screws.

  • Make sure the engine is cold before you start your inspection, and remove all protective shields and covers on the engine to improve your chances of spotting the leak.
  • If the valve cover gasket is leaking, oil will have collected in the gap between the cover and the cylinder head, but it will also have left a trail as it ran down the engine. If the trail stops at the gap, it is certain that the gasket is leaking.
  • Use the correct tool to check all bolts or screws holding the valve cover down for tightness, and tighten any that are not fully screwed down. Wipe off as much leaked oil as possible, and operate the vehicle normally to see if the leak returns.
  • If the leak does return, replace the gasket with an OEM replacement to ensure a proper fit, but bear the following in mind-
    • Once the valve cover is removed, clean all mating surfaces with a lint-free rag and a solvent such as acetone to remove oil residues. Doing this improves the sealing properties of the new gasket greatly
    • Do NOT use silicone sealants on rubber gaskets, because not only do these sealants do nothing to improve the sealing properties of rubber gaskets, but because uncured silicone sealants can become detached and end up clogging oil passages and galleries, with potentially disastrous results for your engine
    • Make sure the replacement gasket fits securely in the valve cover before fitting the cover in place to test the location of the new gasket. DO NOT start inserting and tightening bolts and screws before making sure that the new gasket is properly in place, and not protruding from under the valve cover at any point
    • Insert all retaining bolts or screws, and screw them down in several stages in a crosswise pattern to ensure even sealing of the gasket. DO NOT over tighten bolts or screws- refer to the manual for details on the recommended torque settings for the application.
    • Operate the vehicle normally for a few days to verify that the valve cover is no longer leaking before replacing all protective shields and covers.

Turbo chargers

The most common sites of external oil leaks on turbo chargers is where the oil return line connects to the underside of the turbo charger body. On most applications, this line is a rubber, oil resistant hose that connect to the oil pan. However, the high temperatures associated with turbo chargers cause these hoses to harden, split, or crack, which causes major oil leaks that give off intense clouds of smoke when the oil comes into direct contact with the searingly hot turbo charger casing. The only remedy for this type of leak is replacement of the hose with an OEM replacement part. Note however, that while many aftermarket parts suppliers claim that their hoses are and temperature resistant, aftermarket hoses seldom provide the level of durability and reliability that OEM hoses do.

NOTE: It should be noted that accessing the oil return hose on many applications is far easier said than done. On many applications, working space is severely limited, and to reach the hose it may be necessary to remove or disassemble unrelated parts and components. If you have any doubts about your ability to perform the replacement yourself, the better option is to refer the vehicle to a competent repair facility for professional assistance.

Oil seals

Oil seals that commonly leak are the crankshaft seals both on the front and back of the engine. In the case of the front seal, this seal is always located out of reach behind the harmonic balancer (crankshaft pulley), and replacing these seals involve removal of drive belts, A/C pipes and hoses in some cases, the harmonic balancer itself, and the timing cover along with the timing belt if the engine uses an external timing belt.

If the rear seal (commonly known as the main bearing seal) is leaking, engine oil can often be seen dripping out from between the engine and the transmission. The only way to replace this seal is to remove either the engine or the transmission form the vehicle- which is removed depends on the application.

Other seals that often develop leaks are those that seal the camshaft(s) on engines that use external timing belts. Replacing these seals requires removal of drive belts, A/C pipes and hoses in some cases, the timing cover along with the timing belt, and in many cases the valve cover, and camshaft(s) as well.

WARNING: Attempting to replace the oil seals described here is NOT recommended for non-professional mechanics that do not have the required skills, tools, equipment, and technical abilities. Oil seal replacement is a highly technical procedure that should ideally ONLY be performed by trained technicians that have access to the special tools and technical knowledge that are often required to perform seal replacements successfully.

Transmission leaks

Both manual and automatic transmissions most commonly leak through the output shaft or selector shaft seals, though one or more sensors that are screwed into the transmission, and in the case of automatic transmissions, at the point where fluid cooling lines attach to either the transmission and the radiator or fluid cooler, or sometimes, at both attachment points.

Other possible leak sites include the mating surface between the transmission and the oil (fluid) pan, the point where the dipstick tube enters the transmission casing, or the drain/filler plug(s).

The repair depends largely on the site of the leak, but non-professional mechanics are strongly urged to refer transmission leaks to a competent repair facility for professional diagnosis and repair, since some repairs could include removal and disassembly of the transmission.

Power steering fluid leaks

On older vehicles, the most common sites of fluid leaks is the high pressure hose that hardens, which allows fluid to escape from between the hose and the crimped metal fittings, but also through the braids of the hose itself. Replacement of the hose with an OEM replacement hose is the only reliable, long-term remedy.

Other leak sites could include joints and attachments point in the low-pressure hose, or the power steering rack itself. While replacing the low-pressure hose should not present most non-professional mechanics with undue difficulties, all other repairs should be referred to the dealer or other competent repair facility for professional diagnosis and repair.

Engine cooling system leaks

While oil leaks usually give off an acrid, chocking odor that is often accompanied by thick clouds of white smoke, leaking engine coolant usually gives off a sweetish, almost pleasant smell when the antifreeze comes into contact with hot engine parts.

Since coolant leaks can occur (often unexpectedly) anywhere in the cooling system, the best way to prevent leaks is to perform regular inspections of the radiator, hoses, and expansion tank, and to make repairs or replace parts as soon as possible after a problem is discovered.

If however, a leak develops suddenly, DO NOT attempt to stop it by covering the site of the leak with your hands, or objects such as jackets, sweaters, or other items of clothing. Trying to cover or stop a leak will almost certainly cause you to sustain serious injuries, since the escaping mix of coolant and steam is super heated and highly pressurized.

WARNING: Required repairs depend on where the leak occurred, but NEVER work on the cooling system when the engine is hot. Also, note that refilling the cooling system after repairs often require that air be purged from the system in a prescribed procedure, so always refer to the manual for the application for details on how to purge the cooling system successfully. Getting this step wrong can cause serious and often fatal engine overheating.

BURNING RUBBER ODORS

The odor of burning rubber on a modern vehicle is a somewhat rare event, since most engines are designed in such a way that rubber hoses and components are routed and secured away from hot exhaust parts.

However, if you do smell rubber burning under the hood, keep a fire extinguisher (if you have one) ready at hand when you open the hood, since opening the hood can cause smouldering rubber to ignite into actual flames when additional oxygen is added when the hood is lifted.

Typical sites of heated rubber include unsecured or badly routed radiator, A/C, or power steering hoses that rub against drive belts or other rotating parts, or drive belts that are slipping on frozen/seized pulleys and/or tensioners. Repairs or remedial action depends on the actual problem but bear in mind that rubber that is hot enough to give of a bad odor is extremely hot, so DO NOT touch the problem area/object with your bare hands- doing this can cause serious scalds and burns. Wait for the engine to cool down before you attempt repairs.

BURNING INSULATION ODORS

Burning electrical insulation always indicates a serious problem, since many, if not most engine and vehicle fires start as the result of short circuits that melt protective insulation around wires and cables.

Electrical short circuits have many possible causes, including badly and secured wiring that rubs against body or engine parts, wiring that runs to close to hot exhaust or turbo charger components causing insulation to melt, or often, poorly executed repairs that leave live wires exposed.

Whatever the cause of the short circuit, the best thing to do when insulation starts to burn is to switch off all electrical consumers, and to exit the vehicle as soon as it is safe to do so; i.e., don’t stop the vehicle in the middle of traffic and jump out just to get driven over by a passing bus.

If it is possible to open the hood and you see an actual fire, get as far away from the vehicle as you can if you have no means of fighting the fire. Bear in mind though that if there is no actual fire, but you see the site of the burnt/burning insulation, DO NOT touch the damaged wiring with your bare hands- if you do, you will almost certainly sustain serious burns.

BURNING PLASTIC ODORS

Many modern vehicles have a lot of plastic in the engine compartment these days- from protective shields and covers, to plastic inlet ducting, and other components. Under normal driving conditions, these components rarely melt or catch fire, but lost and/or broken retaining clips often cause shields, covers, and other components to move into close proximity with hot exhaust parts, where they can melt and give off an acrid, choking odor and sometimes, clouds of black smoke.

If you encounter such a situation, switch off the engine to reduce the heat acting on the plastic part or component, but do NOT touch the object with your bare hands, since the object is almost certainly hotter than you might have thought. Use an object of clothing or a rag, newspaper, or other insulating material to remove the melting/melted object from the engine compartment to avoid burning or scalding yourself. Let the engine cool down and remove all, or as much as possible of the melted plastic material from where it had fused onto the hot surface before continuing your journey to avoid the possibility of the remaining material starting a fire.

BURNING FRICTION MATERIAL ODORS

On front-wheel drive vehicles that have manual transmissions, the clutch is located under the hood, since the engine and transmission combination set is located transversely. Therefore, if the clutch starts to slip for whatever reason, the acrid odor of burning friction material will emanate from under the hood, as opposed to coming from under the floor pan on rear wheel drive manual applications.

Note that on some applications, the same, or almost the same odor as that of a burning clutch might appear to come from under the hood if the front brakes are overheating. While a burning clutch can be confirmed if the engine speeds up but the vehicle does not accelerate, overheated brakes can be identified by either a mushy feel to the brake pedal, or a serious reduction in braking performance when the brakes are applied.

In both cases, repairs are best left to the dealer or other competent repair facility. In the case of overheated brake parts, other components such as sensors and/or wheel bearings may have been damaged by the excessive heat as well, while removal of the engine or transmission is required to replace a damaged clutch.

Reiner’S CORNER – AUTO REPAIR HELP
DIAGNOSE – THE STEERING HAS EXCESSIVE PLAY AND FEELS LOOSE Part 2 by Reiner B.

Continued from Part 1

DIAGNOSING STEERING AND SUSPENSION TIPS & TRICKS

WARNING: Note that servicing, repairing, or replacing suspension and steering components require equipment and a degree of skill/mechanical aptitude that novice DIY mechanics generally do not possess. For this reason, it is recommended that all suspension and steering system repairs be left to professional technicians, or at least, to non-professional mechanics that have some experience of working on these systems.

Almost all steering and suspension components fall into the “[these are] life and limb parts” category, which makes it vitally important to address all and any issues with these systems without delay, or preferably, immediately when problems such as imprecise steering, uneven tire wear, poor steering response, or difficulty with maintaining directional control arise.

Bear in mind that many, if not most steering and suspension parts are not easily accessible, and often remain ignored or overlooked during routing servicing or maintenance procedures. Long experience in the auto repair trade has shown that car owners are often unaware of defective, damaged, or broken steering and/or suspension components on their vehicles. In many cases, these defects are discovered accidentally, or worse, only after a crash that was caused by a defective steering /suspension system component had already occurred.

Nonetheless, steering and suspensions systems usually do not fall apart or fail catastrophically without giving at least some advance warning. If these warning signs are heeded, major issues can generally be avoided, simply by repairing, or replacing components as the wear out, Failing to do this in a timely manner usually turns relatively small routine maintenance chores into major repair efforts (and hefty repair bills), since all steering and suspension components have a direct effect on all other parts and components in these systems.

If you have issues with uneven tire wear, a vehicle that pulls to one side or a generally “sloppy feel” to the steering on your vehicle, work your way through this quick guide to steering issues to help you identify the problem. Here is what to look out for when-

TIRES WEAR UNEVENLY

Tires that show accelerated wear either on the inside or outside shoulders is a sure sign of poor wheel alignment, which can have several causes such as-

  • Worn tie-rod ends
Tie rods connect the steering rack to the steering knuckle or wheel hub, and excessive free play in these parts causes the front wheels to lose their alignment relative to each other. This usually results in a condition called toe-out, which wears the tires on the inside shoulders, since the “fronts” of the tires point away from each other.

Worn tie-rod ends usually causes the vehicle to “wander” across the road, since the angle between the two front wheels change constantly, with the degree of “wander” largely depending on the amount by which the angle between the wheels change. The vehicle may also pull to one constantly, or sometimes, only when the brakes are applied.

  • Worn ball joints

On applications that use Macpherson struts, the bottom of the strut is connected to a control arm with a ball joint. In this arrangement, the control arm forms one side of the triangle that represents the suspension “cradle”, with the other two sides being the strut, and the vehicle itself, respectively. In practice, the ball joint both allows the suspension to move up and down, and the steering knuckle to pivot, which allows the front wheels to deviate from the straight ahead position in response to steering inputs.

If the ball joint wears out, the wheel loses its camber setting, which is a setting that deviates slightly from the dead upright position. Camber is one of the settings that influence straight-line tracking, and hence, directional stability. Worn ball joints usually (but not always) result in tires wearing rapidly on the inside shoulder.

Incorrect camber usually causes poor steering response, an imprecise “feel” to the steering, or in some cases, a constant pull to one side, especially when the ball joint on only one side is worn.

  • Worn Macpherson strut mountings

Macpherson struts are connected to the vehicle frame with a flexible, resilient rubber mounting that incorporates a bearing to allow the strut to pivot in response to steering inputs. Over time, these mounting can lose some or all of their ability to hold the top of the strut in position, which results in a loose, sloppy feeling to the steering. Other symptoms could include a reduced straight-line tracking ability, and severe knocking or thudding sounds when the vehicle travels or uneven road surfaces.

  • Worn control arm bushings

Control arms are connected to the vehicle frame with resilient, flexible bushings that allow the control arm to move up and down along with other suspension components in response to bumps in the road surface. Over time, these bushings can lose some, or all of their ability to control the lateral movement f the control arm, which usually results in poor steering response, poor wheel alignment, and accelerated tire wear, and even reduced braking performance on some applications.

Note that the suspension systems on some applications (particularly pickup trucks), have two “A”-shaped control arms on a side that are each connected to the vehicle frame with two bushings, but also to each other via the steering knuckle with two ball joints. One ball joint connects to the top, and one at the bottom of the steering knuckle, with the whole forming a moveable structure that allows up and down movement, as well as a means for the steering knuckle to pivot, via the two ball joints.

Excessive free play in one or more bushings and/or ball joints on double control arm suspension systems can cause poor steering response, poor wheel alignment, accelerated tire wear, and in some cases, reduced braking performance.

  • Worn steering rack

Almost all light vehicles use rack-and pinion steering systems that consist of a straight bar (the rack) with teeth cut into them that engage with teeth cut into the pinion, which is connected to the steering wheel. As the steering wheel is turned, the teeth on the pinion move the rack, thus creating the steering action.

While there is not much that can go wrong with the teeth on the rack or the pinion, the rack slides through two tough, but wearable, bushings in the ends of the tube that houses the rack. When these bushings wear out, the rack is no longer held firmly in position, with the result that some of the turning moment from the steering wheel is taken up by the excessive clearance between the rack and the bushes. In practice, this causes a loose, sloppy feel to the steering, and maintaining directional control can become difficult at high speeds.

  • Worn draglink components

Applications that use double control arm suspension systems usually do not use rack-and-pin steering mechanisms; instead, these applications use a steering box that acts on only one front wheel. The steering action is transferred to the other wheel with a bar known as a “drag link”, which, while it is attached to both steering knuckles, is further supported by one or more idler arms that are attached to the vehicle chassis.

Thus, when the steering wheel is turned, the steering action is transferred to the other wheel, and in a fully functional steering system, both wheels will pivot by the same amount. However, draglinks typically have many pivot points that can wear out, which means that depending on which points are worn out, the front wheels may not turn by the same amount when the steering wheel is turned.

Typically, worn draglinks cause a delay in steering action, poor steering response, reduced, or poor straight-line tracking, and reduced braking performance. In some cases, the vehicle may wander across the road so severely that maintaining directional control becomes difficult, if not impossible at high speeds.

HOW TO DIAGNOSE EXCESSIVE FREE PLAY IN STEERING SYSTEMS

While all of the above should provide most non-professional mechanics with some background information on why steering systems sometimes develop a sloppy feel, actually finding a defective component, and worse, determining whether free play in that components is excessive or not, can be a tricky affair.

However, while there are ways of detecting defective components definitively, the best way of doing it requires that the vehicle be on its wheels, with its full weight acting on the suspension and steering systems. Lifting the vehicle off the ground extends the suspension, which can have the effect of removing free play between components since the various parts of the suspension, and often the steering system as well, are now locked or wedged against each other, which makes relative movement between components almost impossible. Therefore, here is what to do-

Place the vehicle on a four-post vehicle hoist

Hoists of this type have two platforms on which the vehicle can rest on its wheels while it is being lifted off the ground. Of course, few non-professional mechanics have access to this type of vehicle but assuming that readers of this post have access to a suitable hoist, place an assistant in the vehicle, and hoist it to a height that is comfortable for you when you are under the vehicle.

NOTE: Make sure to engage the parking brake while the vehicle is on the hoist to prevent it rolling off.

Make sure you have a powerful flashlight or other light source available, and perform a thorough visual inspection of all visible suspension and steering system components from underneath the vehicle. Look for obviously damaged or broken components, but bear in mind that damage to some components will not always be apparent or visible.

Next, have the assistant in the vehicle turn the steering wheel rapidly from side to side, but only until a resistance is felt; this usually requires less than a quarter of one revolution of the steering wheel in either direction. Note that on applications with power steering, starting the engine may be required to achieve the desired effect.

Moving the steering wheel in this manner will reveal-

  • Free play in tie rod ends
  • Free play in the steering rack
  • Free play in drag link pivot points, idler arms, and sometimes in control arm bushings

Instead of moving in the direction that is dictated by the design of the steering system when the steering wheel is moved, parts may move up, down, sideways, or in other ways that clearly demonstrate movement relative to each other. Ideally, steering system components should only rotate around each other, and any movement away from each other indicates that the components are worn.

Next, obtain a 24-inch crow bar (aka pry bar) with a flattened point, and insert it between the bottom of the control arms and the ball joints, but take great care not to damage the wheel speed sensors and their wiring, brake lines, and other parts and components. The object of this test is to attempt to pry the various components being checked away from each other; if excessive free play is present, it will become apparent as movement relative to each other. Ideally, ball joints should only allow rotation; any other movement indicates that the part is worn. Using firm pressure, test all the ball joints by attempting to pry them away from the control arm or steering knuckles.

Test the control arm bushings in the same way. Insert the pry bar into a point between the control arm and the frame of the vehicle as close to the bushing as possible, and apply a levering force to gauge the resilience of the bushing. However, note that while there must be some movement (since the bushing is designed to be resilient), there should be no free movement in any direction. All movement must be against a firm resistance; if there is no resistance or if you hear a clunking noise when you apply a levering force the bushing are worn, damaged, or broken, and likely the cause of the sloppy feel to the steering.

ONE MORE THING…

Bear in mind that all of the issues, problems, defects, and faults described above can produce uneven or accelerated tire wear, since the alignment angle between the front wheels are directly impacted when almost any steering or suspension system component wears out, breaks, or becomes unserviceable for whatever reason.

Note also that stripping down and reassembling the steering and suspension systems for the purposes of making repairs can (and almost always does) destroys the original wheel alignment settings. Therefore, it is critically important to have a proper wheel alignment check performed by competent technicians whenever repairs have been made to the steering or suspension systems.

 MARK’S CORNER – AUTO REPAIR HELP

DIAGNOSING ENGINE OVERHEATING
by Reiner B.

Continued from Part 1

ENGINE OVERHEATING DIAGNOSTIC TIPS & TRICKS

It should be noted that while engine overheating cannot always be prevented or avoided, drivers are often presented with several warning signs that if observed, can limit the damage that comes with engine overheating, or even prevent a disastrous occurrence of engine overheating altogether.

However, since the causes of engine overheating are not always immediately apparent, there are several diagnostic checks most car owners can perform themselves to diagnose and identify issues/symptoms that can develop into serious engine overheating and even catastrophic engine failure if these warning signs are ignored or not attended to in a timely manner.

To help you interpret the warning signs of a potentially fatal episode of engine overheating, use the following questions (and the answers to them), to help you avoid a misdiagnosis, starting with-

Is it necessary to top off the coolant level regularly?

Since there is no such thing as a perfectly sealed engine cooling system, some coolant loss is to be expected. Typical sites of coolant loss is past radiator caps that have lost some of their spring tension, expansion tank caps that have less than perfect seals (or have not been tightened properly), seepage past hose clamps, and pinhole leaks in radiators, heater valves/heat exchangers, and the mechanical seals in water pump.

On vehicles that are in a good to reasonable state of repair, these coolant losses should not amount to much, and topping off the coolant level with a few ounces of coolant every several weeks or so should not be an issue.

However, if it becomes necessary to top off the coolant level every day, or even every few days, there is a serious leak present that MUST be found and repaired without delay to prevent the possibility of catastrophic engine failure due to fatal overheating.

Are there no visible fluid leaks?

On some applications, it can be very difficult to spot coolant leaks, but one way of making it easier is to add a few ounces of brightly colored food coloring to the cooling system when the engine is cold.

The next time the cooling system is hot and pressurized, the food coloring will leave a stain at and around the site of the leak, which makes it easier to find the exact site of the leak.

No fluid leaks, but the heat gauge shows an abnormal reading?

Note that an engine can overheat fatally even if the temperature gauge shows a below normal reading. Here is how to find out what is going on if the coolant boils out, but the gauge shows a normal, or even a below-normal reading-

WARNING: Use extreme caution during this step to avoid sustaining burns and scalds, and REMOVE ALL JEWELLERY AND LOOSE CLOTHING THAT CAN BE CAUGHT IN DRIVE BELTS, PULLEYS, AND OTHER MOVING PARTS.

  • Let the engine cool down- preferably overnight. Check that the coolant level is up to its proper mark, start the engine, and allow it to idle. Locate both the radiator hose that enters the top tank on the radiator, and the bottom hose that channels cool water back to the engine. While monitoring the heat gauge, periodically touch both hoses, but bear in mind that the top hose will feel hotter to the touch sooner than the bottom hose will.
  • The purpose of this exercise is to determine if the thermostat is working or not. Since the thermostat is a valve that regulates the flow of coolant, the bottom radiator hose should slowly heat up as the engine heats up. In practice, heat is transferred to the thermostat by convection, and if the thermostat works as intended, it will open when the coolant that is in contact with it reaches a preset temperature.
  • At this point, you will feel a sudden increase in the temperature of the bottom radiator hose, which should be nearly as hot as the top hose is when the thermostat opens, which allows coolant to circulate through the engine.

WARNING: It is critically important to monitor the temperature gauge during this step, since the coolant temperature switch monitors the temperature of the coolant in the cylinder head regardless of whether the thermostat opens or not. Thus, if the bottom radiator hose does not heat up or reach the same temperature as the top hose by the time the temperature gauge indicates a normal reading, the thermostat is stuck closed, and by definition, defective.

NOTE#2: If all the other components of the cooling system work as intended, the electric radiator fan should start within a few seconds of the two radiator hoses reaching the same temperature.

WHAT TO LOOK OUT FOR AT THIS POINT

  • When the radiator fan starts, the temperature gauge should show a normal reading. However, if it shows an abnormally high temperature, the thermostat is defective in the sense that it opens either too late, or not completely.
  • As soon as the radiator fan starts, it will begin cooling down the coolant that is flowing through the radiator, and it will shut off automatically when the coolant reaches the desired temperature. However, the drop in temperature should be reflected on the temperature gauge; if the gauge does not reflect a drop in temperature and the fan keeps on running, the fan is either not rotating at the correct speed, or the thermostat is not closing. The latter condition does not allow the coolant enough residual time in the radiator to cool down, and the engine could suffer fatal overheating even if the coolant circulates freely through the engine via a fully open thermostat.
  • Note that if the thermostat does not close, it is possible to see an abnormally low coolant temperature at low road and engine speeds because the coolant is circulating slowly, and has sufficient time to cool down in the radiator. However, as the engine speed rises, the water pump spins faster, causing the coolant to circulate at a rate that does not allow sufficient time for the coolant to shed heat effectively. In this condition, it is almost certain that the engine will seriously overheat at some point.

NOTE #1: Coolant circulation issues always require replacement of the suspect thermostat, since thermostats are NOT repairable.

NOTE#2: While it is possible to replace the thermostat on many applications on a DIY basis, it should be noted that the procedure almost always requires removal or disassembly of other, unrelated engine components. If you have doubts about your ability to perform the replacement, the better option is to refer the vehicle to a competent repair facility for professional assistance, since it is easy to make mistakes if you are not skilled at this level of car repair.

Does the engine run rough upon start up, and then smoothes out after a few seconds?

If this happens, it is almost certain that coolant is being pushed through leak paths in the cylinder head gasket(s) or cracks in the cylinder head when the cooling system is hot and pressurized. If the leak is small, the coolant is partially burned and/or expelled through the valves when the engine is running. If however, the leak is bigger, the residual pressure in the cooling system forces coolant into the cylinders when the engine is turned off.

Thus, when the engine is started again, the coolant in the cylinders fouls the spark plugs on gasoline engines, or inhibits the combustion process on diesel engines, with the result that the engine runs rough until all the coolant is expelled from the cylinders.

Note though that in severe cases, so much coolant can collect in the cylinders that the engine can be prevented from turning over, and in some cases, connecting rods, and even crankshafts can bend or break if the engine is forced to turn over.

This type of problem is common when cylinder head gaskets blow for whatever reason, and the only reliable, long-term remedy is removal of the cylinder head(s) and replacement of the cylinder head gasket(s). Note however that this procedure is best left to professionals who have the skills and knowledge to both diagnose and recognize the root cause(s) of the blown head gasket(s), as well as additional damage to other engine parts and components that may have been caused by the initial overheating that had caused the gasket(s) to blow.

Partial head gasket failure is a major cause of engine overheating since combustion pressure is allowed to enter the cooling system, which can force the coolant out of the cooling system either past the radiator cap seal, or through a burst radiator hose.

NOTE: The surest way to detect leaking cylinder head gaskets is to perform a chemical test (or to have it performed by a competent technician) in which a reagent is brought into contact with the coolant while it is circulating through the engine. If exhaust gasses are present in the coolant, the reagent will change color, usually from blue to yellow. Unlike other tests, such as leak down and pressure tests, this chemical test can detect minute leaks in head gaskets that other tests cannot.

HOW TO RECOGNIZE A BLOWN CYLINDER GASKET

There are several ways to detect a leaking cylinder head gasket. Here is how-

  • Even if the engine is not misfiring, a white, milky residue under the oil filler cap is a sure sign of a blown head gasket. Note that the absence of this residue ( which is an emulsion of engine oil and coolant) in the oil pan or elsewhere in the engine is not necessarily an absence of evidence of a blown gasket, since the engine oil and coolant do not always mix when head gaskets blow
  • If two adjacent cylinders have lost an equal amount of compression, the gasket is leaking between those cylinders, or the cylinder head is cracked between those cylinders.
  • Note however that gaskets do not always blow between two adjacent cylinders. In some cases, the leak path opens up between a cylinder and the coolant jacket around the cylinders, or between a cylinder and an oil passage. In the latter case, the engine may exhibit smoking or a hissing sound when the dipstick or oil filler cap is removed while the engine is running.
  • Excessive pressure in the cooling system that causes the coolant to boil, froth, or bubble is a sure sign that combustion pressure is leaking into the cooling system. If this condition has not already caused the engine to overheat, it will do so very soon

Does the electric radiator fan work?

It may be that the electric cooling fan does work, but it may not rotate at the speed required to cool down the engine coolant sufficiently. In these cases, the airflow through the radiator that results from normal, high speed driving may be enough to keep the engine cool, but under slow driving conditions, both the fan’s rotational speed, and the amount of time the fan is spinning is critical for efficient engine cooling.

If you have access to a code reader, use it to measure the fan’s high and low speeds, as well as the temperature of the coolant when the fan activates. Also, scan the OBD system for codes that relate to the fan’s operation, and resolve these codes in the order in which they were stored. OBD II codes that may be present will relate to the fan motors’ speed, as well as codes that relate to the operation of the fan switch, which has the purpose of activating and deactivating the electric fan based on the temperature of the coolant.

Is the viscous fan serviceable?

Viscous fans use the shear strength of a fluid to transfer power from the hub to the fan itself, much like how a torque converter uses the shear strength of transmission fluid to transfer power from the engine to the transmission.

If over time, the fluid leak has leaked out of the viscous clutch the fan may no longer be rotating fast enough to create an adequate airflow through the radiator core. One way to test such a clutch is to see if it rotates freely if it is spun by hand. If it does rotate freely, it is defective and must be replaced. If the clutch is serviceable, it must only rotate after a considerable resistance is overcome, but in no circumstances must the fan rotate freely- not even for a partial revolution.

Replacing a viscous fan is generally a relatively straightforward affair, and most DIY mechanics should be able to perform the replacement without encountering undue difficulties.

Is the engine making strange noises?

Most causes of engine overheating are silent, in the sense that they don’t generate sounds or noises that could alert the driver to a problem with the cooling system. In fact, hissing, whistling, or whooshing noises almost always appear when the engine has already fatally overheated. These noises are the sounds of superheated steam escaping under high pressure.

Nonetheless, there is one exception to this rule, and it involves the condition of the water pump. While water pumps generally have reasonably long service lives, their support bearings start to wear out when coolant starts to leak past the mechanical seals that contain the pressurized coolant.

The first sign of a worn water pump is usually a rumbling noise that is caused by coolant in the bearings that washes out the bearings’ lubricant) that increases in intensity as the engine speed rises. Note that this is not always accompanied by coolant leaks when the engine is running. In the early stages of water pump failure, some coolant may sometimes be seen dripping from the pump only after the engine is switched off, and while the cooling system is pressurized.

If a noisy water pump is not replaced in a timely manner, the bearings can fail catastrophically at any time, which usually causes the pump internals to disintegrate, but with the added bad news that the radiator and other components can be destroyed by the drive belt when t is flung off its pulleys at high engine speeds.

OTHER CAUSES OF ENGINE OVERHEATING

It is perhaps worth noting that engine overheating can occur through causes that do not directly involve faults and defects in the cooling system. These causes could include the following-

Blocked/restricted exhaust systems

A restricted exhaust system prevents the efficient extraction of exhaust gasses, which causes excessive backpressure to develop, which in turn, can raise cylinder head temperatures on some applications. Note though that although this type of problem will usually set dedicated fault codes on OBD II equipped applications. OBD I equipped and earlier vehicles, on the other hand, do not have these “early warning systems”, and may experience serious engine overheating issues due to exhaust system issues.

Incorrectly set ignition timing

This mainly apples to older applications that have adjustable ignition timing; over advanced ignition timing can raise combustion temperatures to the point where the cooling system cannot cope with the added heat.

Driving in the wrong gear

This applies to both new and old vehicles, and particularly vehicles that have manual transmissions. Driving while in an appropriate gear, such as driving in top gear when towing uphill, lowers the engine speed, which in turn, lowers the rotation speed of the water pump. Under these conditions, the use of large throttle openings in an effort to maintain speed raises the combustion temperature, which cannot be effectively shed by the low rate at which the coolant circulates.

Carl’s Corner – Auto Repair Help
DIAGNOSE – THE TURN SIGNALS DON’T WORK OR DON’T WORK PROPERLY Part 2 By Reiner B.

Continued from Part 1

TURN SIGNAL REPAIR TIPS & TRICKS

One of the most common issues with turn signals is short circuits between live contacts and ground, or other circuits. When this happens, you are likely to either see a brake or head light bulb flash along with the turn indicator bulb when the turn signals are turned on, or the turn signal bulb lighting up when the brakes are activated or the headlights are turned on.

While these types of short circuits do happen on cars and SUV’s, it is more common on pick-up trucks, and particularly on trucks that see a lot of off-road use since the rear light clusters and wiring on these vehicles are not as well protected as the wiring on other types of vehicles are. However, since the same issues that affect pick-up trucks affect cars and SUV’s as well, the simple diagnostic steps outlined here should resolve the issue nine times out of every ten, regardless of the vehicle type.

NOTE #1: Note that to diagnose inoperable turn signals you may need to have access to a repair manual that includes a wiring diagram for the affected application. If a repair manual is not available, a suitable wiring diagram can often be found free of charge with an online search. Note that you will also require a good quality digital multimeter; simple test lights are mostly useless since they cannot measure electrical resistances in circuits accurately.

NOTE #2: As with all car troubles, approaching the issue of defective turn signals in a logical manner saves time and prevents misdiagnoses, so start the process with asking yourself the following questions, starting with-

Are all the turn signal bulbs affected?

  • If all the turn signal bulbs are out, check the relevant fuse(s), but do NOT replace blown fuses until the short circuit that had caused the fuse to blow had been found and repaired.
  • If the fuse is intact but shows signs of overheating, do NOT replace the fuse until the abnormal resistance in one or more circuits is repaired.
  • If the fuse is intact and does not show signs of overheating, it is likely that the flasher relay is defective, but do not replace the relay until you have verified that the circuit that supplies the relay with power is intact, or not.
  • Refer to the wiring diagram to identify the wires feeding the turn signal relay with power, and verify the current in this wire with the ignition “ON” without the engine running. Note that on applications with solid-state relays, the input specified current may be less than battery voltage, so compare all obtained readings with the values stated in the manual before drawing any conclusions about the state of the wiring.
  • If the turn signal relay input current agrees with the value stated in the manual, measure the relay’s internal resistance, and replace it if this value deviates from the manufacturer’s specified value. Test the turn signals after the relay is replaced to verify that ALL the bulbs are flashing at the same rate. Also, turn on the hazard switch to verify that the turn signals work with the ignition in the “OFF” position.

NOTE: Some types of turn signal relay failures can cause all the turn signal bulbs to illuminate, but not to flash. While there are other causes of this, in the vast majority of cases a replacement of the turn signal relay with an OEM replacement part will resolve the issue.

Are only some turn signal bulbs affected?

If only some bulbs are affected, it is important to check if the affected bulb is only illuminating weakly, or if it is well and truly dead, since weak illumination can indicate a short circuit. Here is what to look for-

Are all the bulbs on only one side of the vehicle working?

If this is the case, suspect either a defective turn signal switch, or a defective turn signal relay. If replacing the turn signal relay does not fix the problem, replace the turn signal switch but be aware that removal of the steering wheel may be required, which could trigger the steering wheel (or other airbag(s)).

WARNING: If a defective turn signal switch is suspected, the better option is to refer the vehicle to the dealer or other competent repair shop for professional assistance, since triggering an airbag unexpectedly can cause serious personal injury.

Is the affected bulb not illuminating at all?

  • Defective bulbs do not always show physical evidence that they are indeed blown, so replace the bulb with the specified replacement bulb if it does not illuminate.
  • If the replacement bulb does not illuminate either, check the input current from the contact in the bulb holder to ground. Note that on most applications, the contact in the centre of the holder is live, while the surrounding metal body of the holder is grounded.
  • If the multimeter shows the correct current, the contact between the bulb and its holder is poor, so use long-nosed pliers to deform the edge of the bulb holder SLIGHTLY to improve contact between the bulb and its holder. If the bulb now illuminates and flashes at the correct rate, the problem on that turn signal is resolved.

Is the replacement bulb still not illuminating?

If the bulb does not illuminate and multimeter shows the correct current on the live contact (as per the steps above), test the ground circuit between the outer metal part of the bulb holder and a known live wire that does not feed a turn signal. If the bulb holder is grounded properly, the multimeter will show a constant current; if there is no ground, the multimeter will show an open circuit. Finding and repairing the open ground circuit will resolve the problem, provided that the bulb is good, and that there is proper contact between the bulb and its holder.

Is the affected turn signal bulb illuminating weakly?

  • If this is the case, remove the bulb and use the multimeter to verify that the specified input current is present on the live contact. If not, remove the entire light cluster from the vehicle and inspect the connector that connects the cluster to the main wiring harness for looseness, corrosion, or mechanical damage that could conceivably cause a loss of current. Remove all corrosion if possible, or replace the connector as required and test the turn signal.
  • If the problem persists but there is no corrosion of the connector, it is undamaged and fits securely, test the input current on the VEHICLE side of the connector. If the current is low, inspect the wiring all the way to the turn signal relay, and repair or replace wiring as required to repair the abnormal resistance or poor contact. Test the turn signal after repairs are complete to verify the repair.

Are the turn signals flashing too fast / too slowly?

Since turn signal relays generally depend on a resistance spike to act as a trigger to switch between “ON” and “”OFF” states to cause the bulbs to flash, an excessive resistance will cause the bulbs to flash to slowly, while an insufficient resistance will cause the bulbs to flash too fast.

Typical causes of turn signals flashing to slowly include-

  • Poor electrical contact(s) almost anywhere in the turn signal circuit on the affected side of the vehicle
  • Use of incorrectly rated bulbs
  • Short circuits between the turn signal circuit and other circuits or bulbs

Typical causes of turn signals flashing too fast include-

  • Loss of resistance, such as when one turn signal bulb on one side of the vehicle blows, or stops working due to for instance, loss of ground or contact with the bulb holder
  • Use of incorrectly rated bulbs

Fixing an incorrect flash rate usually involves verifying that all bulbs are rated for the vehicle, and finding/repairing short circuits and/or abnormal electrical resistances. Also, note that the resistance of the indicating light on the dashboard is included in the total resistance of the turn signal circuit, so if the light on the dashboard blows, the flash rate of the turn signals is also affected.

NOTE: Note that one or more of the causes listed above can also cause the turn signals to illuminate, but not to flash on some applications. Be aware however, that distinguishing between a defective turn signal relay and other issues that cause turn signals not to flash can be tricky, and it is recommended that if the steps in this guide do not resolve the issue, the better option would be to refer the vehicle to a competent repair facility for professional diagnosis and repair.

Are other bulbs illuminating along with the turn signal?

  • If this happens, the cause is (almost) always a short circuit in the light clusters’ connector between the turn signal circuit and the circuit that feeds the light bulb(s) that should not flash or illuminate. Remove the light cluster from the vehicle and inspect the connector that connects the cluster to the main wiring harness for looseness, corrosion, or mechanical damage that could conceivably cause a short circuit. Remove all corrosion if possible, or repair/replace the connector as required and test the turn signal.
  • If the problem persists despite having removed all visible corrosion, it is possible that the corrosion had penetrated the cluster to a point where it is beyond saving. However, before replacing the light cluster, it is important to test the brake, head light and other terminals in on the VEHICLE side of the cluster for the presence of a current.
  • If power is present on any terminal in the connector other than the turn signal, inspect the wiring harness that feeds the affected light cluster, and make repairs or replace wiring as required to fix the short circuit.
  • If there is no current on the brake light, head light, and reverse light circuits, replace the light cluster with an OEM replacement part to prevent premature fading of the cluster’s lens(es).

Are some turn signals illuminating at times even when the turn signal switch is “OFF”?

This can happen if there is a short circuit the connector of the affected light cluster, or in the wiring harness that feeds power to one or more light clusters. Depending on the site and severity of the short circuit, applying the brakes, turning on the headlights, or engaging reverse gear can illuminate not only turn signal bulb, but also all the bulbs in a light cluster. Note though that this type of short circuit will not always cause one or more fuses to blow, and the remedy sometimes involves replacing the relevant wiring harness, as opposed to attempting repairs, which is sometimes made difficult by the routing of this harness on many vehicles.

Reiner’s Corner – Auto Repair Help
DIAGNOSE – POWER DOOR LOCKS DON’T WORK PROPERLY
PART 2

By Reiner
Continued from Part 1
POWER DOOR LOCK REPAIR TIPS & TRICKS

Apart from what has been stated in Part 1, diagnosing problems with power door locks is not always a straightforward affair, but one way to avoid confusion and misdiagnoses is to approach the problem logically. Thus, ask yourself the following questions in the order they are presented here, address one issue at a time, and base your actions on the repair options provided in this guide for each question. Also, be sure to check if the problem is resolved after each step both to ensure a successful repair, and to save time.

Are all the door locks affected?
  • If the key fob does not unlock any of the doors, check that the battery in the fob is serviceable, and replace it if there is any doubt about its condition.
  • If the fob battery is new but the door locks remain inoperable, consult the manual to locate the relevant fuse(s), and replace as required with fuses of the CORRECT rating. Note however that blown fuses usually indicate a short circuit, so do NOT replace fuses until the short circuit had been found and repaired.
Do the door locks work now?
  • If the fob battery is new and there are no blown fuses, it is possible that the key fob had lost some or all of its programming. This happens more often than you might think, so have the fob’s programming checked by the dealer or other competent repair shop. In some cases, reprogramming the fob resolves this kind of issue even if there are no obvious programming issues present.
Are the door locks still not working?

If none of the above steps resolves the issue, suspect either a defective door lock switch, or wiring issues. Proceed as follows-

  • Consult the manual on how to remove the switch that operates all the door locks from where it is mounted, and determine the function and color-coding of all the wires that are connected to the switch. Identify the wire that supplies power to the switch, and use the multimeter to verify that the correct voltage is present. If there is no voltage on the input wire, refer to the wiring diagram to find and repair the open circuit.
  • If the input voltage is significantly below the specified value, find and repair the abnormal resistance. This kind of problem usually (but not always) occurs as the result of poor connections across connectors and/or slip joints in wiring.
  • If the correct input voltage is present, it is likely that the switch is defective. However, it is also possible that there is a communication failure between the key fob, the module that controls the central locking/anti/theft system, and the switch. Do not replace the switch (which is expensive) until you are certain that there are no communication issues between control modules. Verifying this is best left to the dealer or other competent repair shop that has access to diagnostic equipment that can access control modules and the CAN (Controller Area Network) bus system.
NOTE: The steps outlined above will usually resolve the problem if all the door locks are affected. Proceed as follows if only some door locks are affected-

Do the affected door locks fail to work consistently?

  • If the failure is consistent, suspect either a wiring issue, or defective door lock actuator, but note that both possible issues require removal of the door panel. Consult the manual on the correct procedure to follow to remove the panel to prevent damage to the panel. Remember to roll up the power window before removing the door panel.
  • Once the door panel is removed and placed safely out of the way, inspect all visible wiring for signs of damage such as chafing, rubbing, burning, or bad connections. Make repairs or replace wiring as required.
  • If no damage to wiring is apparent, consult the manual or wiring diagram to determine the color-coding and function of all wiring that is associated with the door lock actuator. Disconnect the wiring from both the actuator and the main wiring harness and perform resistance and continuity checks to verify the condition of the wiring. Compare all obtained readings with the values stated in the manual, and repair or replace wiring as required to ensure that all electrical values fall within the ranges specified by the manufacturer.

NOTE#1: Pay particular attention to the wiring in the boot between the doorframe and the door itself. Continual flexing of the wiring as the door is opened and closed can sometimes cause conductors within the plastic insulation to fail, with no sign of the failure being apparent during a casual visual inspection of the wiring.

NOTE#2: Be sure to include the affected actuator(s) itself/themselves in this step. Measure the resistance across the two terminals on the actuator(s), and replace it/them if there is no continuity, or if the measured resistance deviates from the value(s) stated in the manual by more than a few percent.

Does the manual switch now activate the affected actuator(s)?

  • Reconnect all wiring, and operate the door lock manually with the switches in the dashboard/console/door panel. All switches should now activate the actuator(s), provided the actuator(s) itself/themselves are in perfect working order. However, since door lock actuators work in both directions because the polarity of their input circuits are reversed by the switches that operate them, it is possible that a switch many be defective if it works in only one direction. For instance, an actuator either locks or unlocks a door, but does not both lock and unlock the door if the switch is manipulated.
  • One way to check if a switch is defective is to connect current from a battery charger directly to the lock actuator. If the actuator works in both directions when the polarity is reversed, the switch is defective.
Do some door locks fail intermittently?

If one or more power door locks fail intermittently, the cause is almost always bad electrical connections. Note though that some types of intermittent failures can be extremely challenging even for professional technicians to find and repair, so if an intermittent fault is suspected, repeat all resistance and continuity tests on all wiring (while vigorously wiggling) the wiring until the fault is found and repaired. Alternatively, refer the vehicle to a competent repair facility for professional diagnosis and repair.

DIAGNOSING MECHANICAL PROBLEMS

Note that many problems with power door locks involve mechanical failure(s) of one or more components, with sticking and/or binding moving parts following close behind. One particular problem, that of locks cycling rapidly (especially on some Honda models) is described below-

Locks that cycle rapidly

On some applications that are fitted with door locks that use DC motors, the control module depends on a voltage spike that occurs when the actuating lever reaches a built-in stop. In these cases, the actuating lever comes to rest against a rubber stop in the switch casing at the end of its travel, which causes a voltage spike that the control module interprets as a signal that the door lock had either locked or unlocked the door.

In many cases, the built-in stop either breaks off or wears away after long use, thus failing to produce the expected voltage spike. When the control module does not receive the expected voltage spike, it either interprets the lack of the signal as a failure of the system, or more commonly, to lock and unlock the door in rapid succession for as long as power is applied to the affected actuator.

Note that the only reliable, long-term remedy for this condition is to replace the actuator with an OEM replacement part to ensure proper operation of the door lock.

Actuators that move slowly

This happens more often on actuators that use DC motors and gears than on actuators that use solenoids. On geared actuators, either moving/rotating parts wear out after long use causing them to bind or stick, or the lubrication inside them dries out, causing the entire unit to bind. Replacement of the door lock actuator is the only reliable remedy.

An example of a typical geared power door lock actuator is shown below. Note the presence of lubricant on the gears that can cause the unit to fail when it dries out, or to fail due to excessive mechanical wear on one or more parts.


Other mechanical issues include mechanical linkages that bind or stick, or door latches that stick or bind due to the build-up of dust and dirt inside the mechanism. Ideally, door latches should not be lubricated, but many mechanics spray all manner of lubricants onto (and into) door latches in efforts to “cure” some power door lock issues. Since few car doors are dustproof, dust and dirt eventually combine with excess lubricant to form a sort of “glue” that inhibits the free movement of parts in the door latch mechanism.

To check if the door latch mechanism is the problem, disconnect the mechanical linkages that connect the power door lock actuator to the door latch mechanism, and activate the door lock. If the actuator now moves freely, the door latch mechanism is sticky or binding. Replacement of the door latch mechanism is the only reliable long-term solution.

NOTE: In some cases, the power door lock actuator is incorporated into the door latch mechanism. On these applications, the entire assembly must be replaced with an OEM replacement part to ensure proper operation of the locking system.

KYLE’S CORNER – AUTO REPAIR HELP

WINDSHIELD WIPER SYSTEM
by Kyle McFadden

The components used in a windshield wiper Winshield Wiperssystem includes a wiper motor, transmission, wiper arms, wiper blades, wiring, switch, module, and washer pump. These items are all available at any auto repair parts shop. The wiper motor is a permanent magnet motor that is capable of multi-speeds. Hi and low wiper speeds are obtained by varying the field current through the motor. This is accomplished by using different resistance paths to ground through the wiper switch. When the windshield wipers are turned off, they are returned to off position by using a park switch. The park switch is designed to deliver voltage to the wipers until they are in their park position.

The transmission converts the rotating motion of the wiper motor to the back and forth motion of the wiper blades. The wiper transmission is a complex series of linkage rods and rotating cams. It is normally located under the plenum in front of the windshield. The wiper arms are designed to properly tension the wiper blades against the windshield. The wiper blades are held against the windshield with enough tension allow windshield clearing without wiper blade chatter. The wiper module allows windshield wipers to operate using a delay mode. The delay mode can command the wipers to operate once every few seconds up to once every 20-30 seconds. The wiper module is a circuit board that contains timers that command wiper operation in response to a signal from a variable resistor in the wiper switch. When the driver sets a wiper switch to a desired delay setting, he or she is actually sending a voltage signal to the wiper module through the variable resistor in the wiper switch.

Windshield washers consist of an electric washer pump mounted in the washer bottle or on the wiper motor, or a mechanical pump operated by the wiper motor. A majority of vehicles use an electric washer pump. When washer operation is commanded by the driver, a pump picks up washer solvent from the washer tank and delivers it via the washer tubing to the washer nozzles. The nozzles are designed to deliver a high pressure spray to the windshield. Most makes of vehicles will deliver a 2 to 3 second spray followed by wiper operation for 5 to 6 seconds.



(Kyle has an affinity for Pale Ale and tooling on his 1956 Chevrolet Nomad Station Wagon.)

JIM’S CORNER – AUTO REPAIR HELP
WHEEL ALIGNMENT
by Jim Miller

Wheel alignment is a measurement Wheel Alignmntof the relationship between certain suspension components, the tires and the rolling surface. Wheel alignment is essential for proper control of the vehicle, efficient steering and to maintain tire life. There are three main adjustments made when wheels are aligned: camber, caster, and toe-in. Camber is a measure of the outward or inward tilt of the wheels. Camber can be visualized by facing the front of the vehicle and imagining the top of the wheels leaning outward, this would be referred to as positive camber. If you were to imagine the top of the wheels leaning inward, this would be called negative camber. Camber is measured in degrees using special equipment. Too much negative camber causes wear on the inside of the tire. Too much positive camber can cause wear to the outside of the tire. Improper camber can also affect the proper steering of the vehicle as well.

Caster is the forward or rearward tilt of the steering axis. Simply put, if you were to stand facing the side of a vehicle and imagine a line extending down through the center of the front wheel, caster would be a measure of how far forward or rearward the line would tilt. If the line were to tilt towards the front of the vehicle, that would be referred to as negative caster. If the line were to tilt towards the rear of the vehicle, that would be referred to as positive caster. Caster is measured in degrees using special equipment. Improper caster settings can cause suspension component wear or damage and can affect steering and tire wear. Toe-in is a measure of the parallel alignment of the front wheels. The best way to visualize toe-in is to stand up and look down at your feet. Imagine each foot is a front tire and you are looking down at the top of a car. By slightly moving the front of your feet inward, towards each other, you would be imitating toe-in on the front wheels of a vehicle. Toe-in is measured in half degree increments. Incorrect toe-in can have adverse affects on the steering of a vehicle.


(Jim is a lifelong fan of Dodger Baseball and used to race sprint cars in the 1980s.)

JIM’S CORNER – AUTO REPAIR HELP

MECHANICAL VEHICLE INSPECTIONS
by Jim Miller

The following list is a recommended mechanical vehicle inspection that should be done on a routine basis, perhaps at each oil change interval. You should refer to your owners manual for recommended service intervals.

DRIVE BELTS
Inspect the drive belts for the correct tension and wear. Worn belts will appear glazed (shinny) and may be cracked on the inside drive surface. A properly tensioned belt will have 1/2″ – 1″ of defelection at the center of its greatest span. Some vehicles use serpentine belts that use automatic tensioners. A serpentine belt is a wide belt that has ribs on the inside surface and is used to drive several accessories. These belts are automatically tensioned.

HOSES
Inspect the hoses and clamps. Hoses should be flexible and free from cracks, abrasions or swelling. Inspect the ends of the hoses for leakage. Retighten the hose clamps as necessary.

AIR FILTER
Inspect the air filter for contamination. Replace as needed. Never blow out an air filter using compressed air. This will remove the tiny particles from the filter media which is used to trap the dirt in the filter, preventing it from entering the engine. Air filter life is usually dependant on driving conditions.

BATTERY
Inspect the water level if the battery is equipped with removable cell covers. Inspect the terminals for corrosion and clean as necessary. A solution of baking soda and water should be used to clean the top of the battery and the terminals. Never put this solution into the battery cells.

VEHICLE LIGHTING
Inspect the head lamps, high beams, turn signals, parking lamps and brake lamps.

TIMING BELT
Replace at manufactures recommended service interval. The timing belt is one of the most common items overlooked and will cause the engine to stall and will prevent the engine from restarting. Some engines can experience severe damage if the timing belt breaks. If you are unsure if the belt has been changed, you should inspect it or replace it to prevent the possibility of breakage. Replacing the timing belt can be an involved job and may require special tools. The timing belt resides behind a protective cover and cannot be visually inspected without the removal of the covers and the belts in front of the covers.

CV BOOTS (Front Wheel Drive Vehicles)
Inspect the CV boots at each oil change. If torn or cracked they should be replaced. For more information on CV joints and boots, refer to the transmission and drivetrain section of this website.

(Jim is a lifelong fan of Dodger Baseball and used to race sprint cars in the 1980s.)

JIM’S CORNER – AUTO REPAIR HELP

CHECKING YOUR VEHICLE FLUIDS
by Jim Miller

The following list is a recommended vehicle inspection that should be done on a routine basis, perhaps at each oil change interval. You should refer to your owners manual for the proper fluid types and recommended service intervals.

ENGINE OIL LEVEL AND CONDITION
Inspect the oil level and condition. If it appears black it should be changed. It is recommended the engine oil and oil filter be changed every 3,000 miles.

AUTOMATIC TRANSMISSION FLUID
Inspect the transmission fluid level and condition. Usually this is done with the engine running at operating temperature, with the transmission in park. Automatic transmision fluid should be red. If the transmission fluid appears brown or has a burnt odor to it, the transmission may require service.

ENGINE COOLANT (Anti-freeze)
Check the coolant level with the engine cold. An inexpensive tester is available at most auto parts stores that will check the level of protection. Most manufactures recommend a 50/50% water and antifreeze mixture. This will protect the engine in temperatures from -30F – +260F.

BRAKE FLUID LEVEL AND CONDITION
Inspect the brake fluid and add as necessary. You should inspect the brakes if the brake fluid level is at the bottom of its operating level. Low brake fluid is the sign of worn brake pads. When the brake pads wear, the pistons in the caliper will extend and will require more brake fluid to reside in the caliper chambers.

WASHER FLUID LEVEL
Inspect the fluid level and add as necessary.

POWER STEERING FLUID LEVEL
Inspect the fluid level, add as necessary. If more than a few ounces are necessary to bring the system to the proper level, an inspection the hoses and fittings for leaks should be performed.

CLUTCH MASTER CYLINDER (If Equipped)
Inspect the fluid level in the clutch master cylinder. Low fluid level could indicate a possible leak.

MANUAL TRANSMISSION FLUID (If Equipped)
Inspecting the fluid level of the manual transmission usually requires jacking or hoisting the vehicle. The plug to access the fluid level is usually mounted on the side of the transmission. Consult your owners manual for location and fluid type.

DIFFERENTIAL FLUID (If Equipped)
Inpsecting the fluid level of the differential usually requires jacking or hoisting the vehicle. The plug to access the fluid level is usually mounted on the side of the differential. Consult your owners manual for location and fluid type.

TRANSFER CASE (Four Wheel Drive Vehicles)
Inspecting the fluid level of the transfer case usually requires jacking or hoisting the vehicle. The plug to access the fluid level is usually mounted on the side of the transfer case. Consult your owners manual for location and fluid type.

(Jim is a lifelong fan of Dodger Baseball and used to race sprint cars in the 1980s.)

KYLE’S CORNER – AUTO REPAIR HELP

VALVE TRAIN & CYLINDER HEADS
by Kyle McFadden

Cylinder heads are cast out of iron or aluminum. Cylinder heads bolt onto the top of the engine block and are used to seal the top of the cylinders. They contain the passages that intake and exhaust gases flow through as well as, passages for coolant and oil flow. The intake and exhaust valves are also located in the cylinder heads. On overhead camshaft equipped engines, the cylinder head will also contain the camshaft.

The valves located in the cylinder heads allow the air/fuel mixture to flow into the combustion chamber and provide a means to remove the combustion by-products from the cylinder. Intake and exhaust valves look similar, but the intake valve diameter is usually larger than the exhaust valve. The large circular end of the valve that faces the piston is called the valve head. The beveled edge of the valve that is on the rear side of the valve head is called the valve face. The valve face is held tightly closed against a circular hole in the cylinder head called the valve seat. The valve seat has an edge that is ground at a different angle than the valve face. This is done in order to allow an interference fit between the valve and the valve seat. This interference fit provides a better seal and helps to center the valve in the valve seat when it is closing. The long shaft that extends from the valve head is called the valve stem. The valve stem extends up through a machined guide into the cylinder head. The portion of the valve stem that protrudes from the top of the cylinder head, is retained by a coiled spring and retainer clips. This coiled spring holds the valve closed.

The valves are opened by a rotating camshaft. The camshaft is rotated by a belt or chain connected to the crankshaft. The camshaft contains eccentric lobes that provide the opening motion for the valve when the shaft is rotated. The camshaft lobes are designed to open and close the valves quickly without damaging them. The round portion of the camshaft lobe is called the base circle. The first part of the eccentric is called the ramp or the flank. The tip of the camshaft lobe is called the nose. The opening ramp is cut in an angle to quickly unseat the valve without causing damage. The nose is cut in a measured distance to hold the valve open for a precise time. The closing ramp is cut at an angle to allow the valve to close quickly without damaging the valve.

The amount of time a valve remains open is called the duration. Duration is measured in degrees. The distance that a valve travels when opening is called the lift. The amount of time that the intake and exhaust valves are open at the same time is called overlap. Changes in engine performance, economy, and emissions can be made by using camshafts with different variations of these measurments.

The camshaft does not directly contact the valve stem. Instead, the camshaft contacts a tappet or lifter, sometimes also referred to as follower. The lifter is used to transmit the action of the spinning camshaft lobe to their respective valves. As the camshaft lobe pushes up the lifter, the lifter in turn moves a long rod called the pushrod. The pushrod connects the lifter to an arm that pivots on a shaft or stud. This arm is called the rocker arm. The rocker arm presses directly on the valve stem on one end and contacts the pushrod on the other. The rocker arm is designed to multiply the lifting action of the camshaft and provide a higher lift to the valve. Overhead camshaft engines work in a similar principle, but use less components. By placing the camshaft on top of the cylinder, the need for complex lifter-pushrod designs are eliminated. While overhead camshaft designs vary from manufacturer to manufacturer, the elimination of the cumbersome lifter pushrod designs, allow an engine to produce power more efficiently.

(Kyle has an affinity for Pale Ale and tooling on his 1956 Chevrolet Nomad Station Wagon.)