Western-Star

Q The trip odometer light burned out in my 2001 Honda Accord. All the other dash lights work just fine. How do I replace it? A.G., e-mail

A Follow all of the factory recommended procedures in a repair manual. The first step is to deactivate the airbag system so that it doesn't deploy. If it does, you could be severely injured or killed.

Once the airbag system is properly disabled, the next step is to remove the instrument cluster from the dash. It's held in the dash with screws and clips. Once it is loose, disconnect wiring from the back of the cluster and fully remove it from the dash.

Once it is out of the dash, replace failed bulbs as needed by removing the bulb sockets from the cluster housing.

Rain stalls engine

Q I have a problem with my 2004 Ford Explorer with a 4.0-liter V-6 engine. When it rains for any length of time, my car stalls and continues to stall. It happens when I slow down, stop for a light or in slow stop-and-go traffic. At times, it is very hard to get the engine to restart and stay on. When I'm driving at normal speeds, everything so far has been fine.

Someone told me this could be caused by a sensor, but they couldn't remember which sensor. I took the vehicle to two different dealers and two different independent repair shops, but nothing shows up on test equipment. Can you help? S.L.,

e-mail

A The computer should store trouble codes indicating a failed circuit or sensor. Since the trouble occurs only in rainy weather, I suspect that the engine control module quits communicating with sensors. This might be the result of moisture affecting electrical connections at the computer. An examination of the connections may find moisture has infiltrated electrical terminals and has caused corrosion. A thorough cleaning might solve this condition.

If the computer electrical connections are fine, it's feasible there is an impairment of the air flow sensor, throttle position sensor or perhaps the crankshaft sensor. There may be a fault in one of these sensors, or the circuit to the sensor has a fault.

It's also possible dirt impairs the operation of the airflow sensor and throttle body. Cleaning could cure a malfunction.

Mysterious engine misfire

Q My 1992 Lincoln Town Car developed a misfire right after I poured Slick 50 into the engine during an oil change service. Since then I have seen several mechanics about the misfire, but none have fixed the problem. One mechanic said the trouble is caused by a faulty oxygen sensor. Another mechanic said the trouble was caused by dirty fuel injectors. One says the problem could be caused by a faulty fuel pressure regulator, and another says the fuel filter needs replacement.

I cleaned the fuel injectors using an over-the-counter additive and replaced the fuel filter, but this didn't cure the trouble.

All of the mechanics tell me that using Slick 50 couldn't cause the engine to misfire. I'm stumped. Do you have any suggestions? C., e-mail

A It's highly unlikely that the product has anything to do with the condition. It's more likely that the misfire is caused by a dirty or faulty fuel injector. Tests can determine if a fuel injector is the cause of your concern.

Also, over-the-counter fuel injector cleaners are not always effective in cleaning years of accumulated deposits from injectors. Professional cleaning is effective in removing deposits. If tests find that a fuel injector is the root of the problem, a professional cleaning likely will restore injectors impaired by deposits.

Tests also will determine if an injector has an internal fault that only replacement will cure.

As for the possibility that the fuel pressure regulator or oxygen sensor cause the condition. These parts also can be tested to determine if in fact there is a fault. If a fault is found replacement is the cure, but it's not likely both parts need replacement.

Hybrid Vehicles Under Scrutiny

Q Hybrid cars seem to be a good solution for today's high fuel costs, but they cost significantly more to purchase than standard gas powered vehicles. Also, there are future repairs such as battery replacements.

How much will it cost to replace the batteries in a hybrid vehicle when they no longer hold a charge? Would you agree that hybrid vehicles are too costly in spite of their fuel savings? B.C., Cottage Grove, Minn.

A Hybrid vehicles are a stepping stone in the development of more fuel efficient vehicles. They are designed and built to reduce fuel consumption and not to reduce overall operating costs that include repairs.

The cost for hybrid vehicle battery pack ranges from about $3,000 to $7,500 depending upon the year, make and model vehicle. During the factory warranty period if a battery pack fails the cost of replacement is paid by the car maker. If you should own a hybrid vehicle beyond the factory warranty coverage when the battery pack fails you will pay for a replacement battery pack, labor and environmental disposal fees.

It's not likely that fuel savings will offset the increased cost of the vehicle over traditional vehicles, preventive maintenance and future repairs related to the hybrid equipment.

A/C Needs Control

Q My 1995 GMC 2500 conversion van with 70,000 miles is in excellent condition but it has been having air flow problems from the front dash vents for the last year and a half. When the control is set to air conditioning or in the vent position the air flow from the front dash vents is intermittent. Sometimes no air flows from the vents.

The air flow seems to have a mind of its own. During a recent 70-mile trip with the air conditioning on, perhaps three times air blew from the front dash vents for three to five minutes each time. Then it blew only on the floor. It was sporadic. The result was very cold feet.

There were times when fresh outside air would be adequate to keep cool if the air blew from the front dash vents, but no air flowed with the fan off or on. The fan operates normally.

I've had this addressed at several garages. The fan motor, a switch and the air canister under the hood were replaced. The problem persists.

One mechanic said sporadic air flow is normal because air coming from the dash vents is controlled by vacuum, and acceleration controls the vacuum. This determines the amount of air coming from the front dash vents. I can't believe this because all the years prior to this problem the air flow from the front dash vents was controlled by the fan speed and it did not vary or stop blowing from the front dash vents on its own and the speed of the van had no effect on air flow.

Can you solve this problem? R.W., Forest Lake, Minn.

A Air flow from the vents should not vary according to engine speed or load. It should be constant. Vacuum motors position diverter doors in the ducts under the dash according to your settings. The vacuum canister is a vacuum reservoir that stores vacuum. Its purpose is to store and regulate a constant measure of vacuum so that the doors in the duct work don't change modes or move with engine speed or load.

The trouble you are encountering likely is caused by a problem in the dash control. Replacement of the control is the likely cure.

Squeak Stirs Up Concern

Q In a recent column I read about M.R. who owns a 2002 Toyota Camry with a noise in the steering. I own a 2003 Toyota Camry with a squeaky steering column. My sister-in-law owns one and it has a squeaky steering column too. This obviously is a genuine defect in the Toyota Camry.

Dealer personnel fixed the trouble in both of our cars under the factory warranty. I was told that once the warranty expires they would continue to treat the trouble with grease at no charge for the life of the car. I asked if they would show my husband how to treat the squeak but they said it would be better for them to do it. I hope that they don't back away from their promise and not charge for the work. If they do I will purchase another make vehicle.

What do you suggest? K.J., E-mail.

A The reader to which you refer was told by dealer personnel that if the squeak returns after the warranty expires there would be a $30 charge to have grease applied to the steering column.

The car manufacturer issued a technical service bulletin to alert dealer shops how to treat a low frequency squeak in the steering column. If shop personnel apply specialized grease at the appropriate location suggested by factory engineers it's likely the squeak will never return. If your dealer followed the procedures in the technical service bulletin you and your sister-in-law will not encounter future inconvenience over this annoyance.

The technical service bulletin also says that during the factory 36 month/36,000 mile warranty there is no charge to the vehicle owner to apply the grease. This means that once the factory warranty expires the factory will no longer pay dealers to squelch the squeak. Since this is the case dealers may charge customers after the warranty expires to have the squeaky column lubricated.

In your case dealer personnel have verbally promised to treat the condition at no charge for the life of the vehicle. Perhaps you should have the promise placed in writing so there aren't any future misunderstandings.

Howling Sound And Vibration Strike Differential

Q I have a 1990 Nissan 300 ZX Coupe with a 5-speed manual transmission and 48,000 miles. It's in perfect condition. It's my baby, my pride and joy.

Recently a howling sound developed in the rear of the car. I also feel a vibration in the floor and seats. In an attempt to fix the trouble the brakes and tires have been replaced, but the howling continues.

What do you think is wrong? M.P.M., E-mail

A The symptoms are consistent with a differential problem. More than likely a failed bearing is to blame. Unfortunately when a bearing fails the ring and pinion gears are damaged as metal fragments contaminate the lubricant. In most cases it is not necessary to replace the planetary gears, but definitely all the bearings and the ring and pinion need replacement as a result of bearing failure.

Ask an experienced technician to consider this suggestion the next time you take your baby to a shop.

Oily Brake Fluid

Q I have a 1995 Buick Park Avenue with 58,000 miles. Recently my mechanic found evidence that there is motor oil in the brake master cylinder reservoir that turned the brake fluid into an oily sludge. He said that the fluid will deteriorate all the rubber parts in the brake system. This will cause the brakes to fail.

Presently the brakes seem to work very well. I didn't pour oil into the brake fluid reservoir but suspect it was poured into system at a quick oil change place.

Is the brake system a goner? Will flushing the brake fluid from the system solve the problem? T.R., St. Paul, Minn.

A This is a very serious condition if in fact motor oil contaminated the brake fluid. Symptoms of the contamination are swollen rubber seals in the master cylinder. Also, the brake fluid becomes dark in color, sometimes black, and the fluid becomes as thick as gelatin. This could result in a sudden failure of the brake system.

Consider this. Don't drive the vehicle until this is resolved. Ask your favorite mechanic to send a sample of the fluid to a laboratory for testing to determine the state of the fluid and if it is contaminated with motor oil. If it is not contaminated with motor oil or another fluid such as transmission fluid there is a good chance that there isn't any serious damage to the system. A flush would be in order. If motor oil or other product is in the fluid all rubber parts and units that contain rubber should be replaced to prevent brake failure.

Loyal Reader Sends Tip

Q In a recent column I read about G.N. who wrote about a sticky shift lever in a 1996 Pontiac Grand Am. You were right when you thought that it was not likely that the transmission needed replacement. I have had luck fixing sticky shifters by simply cleaning the mechanism in the center console. I've found that over time dirt and spilled drinks impair the operation of the shifter. Cleaning could repair the problem.

Can you tell G.N. he may not have to spend $450 to have the trouble repaired if he cleans the shifter? B.H., St. Louis Park, Minn.

A Hopefully G.N. is reading the column today. He has an automatic transmission lever that is so tough to move that he says he nearly has to yank it out of the car.

You are correct. If he is mechanically savvy he can remove the center console trim that surrounds the shift mechanism. Once this is accomplished a thorough cleaning and lubrication may return normal function to the automatic transmission shift lever. If so his troubles may be over. If cleaning and lubrication doesn't do the trick he unfortunately may have to pay to have a failed part replaced.

Thanks for rattling my memory.

Adjustment May Cure Tapping Sound

Q At 45,000 miles my 2001 Dodge Neon with a 2.0 liter engine developed a tapping sound upon the initial start of the day. The tapping subsides as the engine warms. Now the car has 50,210 miles. The car hasn't been abused and has been serviced every 3,500 miles.

A Trade it in. I'm just kidding as usual. What needs to be done all depends on the noise. If it is caused by a valve it's possible a rocker arm needs replacement, but tapping sounds can be caused by a variety of items such as a faulty spark plug wire, carbon deposits in a cylinder, a loose exhaust shield or a worn drive belt. Sometimes even a rubber bushing on the hood could make a tapping sound.

To determine the source of the noise will take some investigation. If you are handy consider purchasing a mechanics stethoscope to probe the engine and other components for the source of the noise. If indeed you verify that the noise is from the valve system it's time to replace excessively worn parts.

If the tapping is caused by a loose exhaust shield or another part address the source of the sound as needed. Depending upon your findings the concern might be solved by a simple adjustment or perhaps a dab of grease.

Air Conditioner Noise Hits High Note

Q When the air conditioner is on in a while my 2002 Volvo S80 every once in a while I hear a high pitched sound like a note from a wind instrument. I hear the sound when slowing down or when stopping for a light. Sometimes I hear the noise when I start the engine. When the air conditioner is off the noise doesn't appear.

I've been complaining about this noise for four years. I took the car to my dealer where a mechanic heard the sound one time, but he couldn't figure out where it came from. The car has been to the shop for this problem several times. Now the warranty has expired. What do you think? S.S., E-mail.

A Sounds that appear only for a short duration and are inconsistent are the most difficult to pinpoint. Since you experience the sound more than anyone, you will have to do detective work to determine the source of the sound. When it occurs try to determine where it is located. It may be behind the glove compartment. Maybe it's in the engine compartment. Try to determine the area of origin. Be as specific as possible and note all the conditions that are associated with the sound. Perhaps the air conditioner has to be set to a certain temperature or blower speed. Maybe it occurs at a certain vehicle speed. What ever you can determine will help a technician recreate conditions that cause the sound. Once you have done this, present all of your evidence to an experienced technician.

From what you describe the noise does not seem to be caused by a serious problem but is an annoyance. It may be caused by air rushing over an object in the ducts of the air conditioning system under the dash. It also could be caused by air rushing over a part in the air conditioning air intake in ducts the cowl in front of the windshield or maybe the engine air intake duct makes a sound at a certain speed. Your help will find the cause.

Oil Pressure Circuit Fault

Q My 1993 Plymouth Voyager with a 3.3 liter engine and 150,000 miles has an oil pressure issue. When I start the engine the oil pressure gauge reads 75 percent. As the engine warms the pressure drops to 25 percent. Sometimes it drops to zero and then jumps back up to 25 percent.

Does this indicate a problem with the oil pump or is there a problem with the oil pressure switch? H.S., Middletown, Ohio.

A The faulty indication likely is caused by trouble in the circuit. There likely is a fault in the oil pressure sensor, wiring or gauge. A technician likely will rule out a problem in the oil pump by connecting a test gauge to the engine. Once he has determined that the pump is functioning normally he will begin to troubleshoot the oil pressure gauge circuit. Once he has done this he likely will find that the connection to the oil pressure sensor or gauge has a fault. Repair might be as simple as tugging on the wire.

Tests Will Find Cause Of Predetonation

Q My 2000 Toyota Avalon has developed a ping sound. A dealership person told me that I should purchase premium fuel. I did but the sound continues. I returned to the dealer where I was told that there is a test they can perform but I will have to pay for the test.

Do you think I should take the car to another shop or let the dealer do the testing? S.K., E-mail.

A It's customary for dealer shops and independent repair shops to charge for tests that they perform on your car. If you went to a doctor and he decided that you needed to go through some tests he would charge you for his advice to have the tests performed and you would be charged for the tests he suggests. Then he would charge for his consultation regarding the results of the tests and charge for follow up treatment.

Once testing on your car is complete it's likely a technician might find that carbon deposits are the cause of the ping or predetonation. It's also possible he may find a faulty antiknock sensor.

If carbon deposits are to blame, removing carbon through the use of special chemicals likely will resolve your concern.

If a faulty sensor is at fault replacing the sensor likely will end your concern. Incidentally it's likely your car has two knock sensors so don't be surprised if both sensors need replacement.

Phil Arendt is a columnist, consultant and A.S.E.-Certified Master Technician. Readers may send questions to Dr. Gizmo at P.O. Box 548, Cary, IL. 60013 or e-mail address drgizmo@drgizmo.ws.