Dear Doctor: I have a start-stall-restart problem on my 2006 Hyundai Azera, which is driving my dealership crazy trying to find the problem. By the time it is towed into the shop it starts right up. I've had it there numerous times and they can never duplicate the condition. It has spent over 34 days and several visits and they cannot get anything on it, even after doing diagnostic testing. Can it be the crankshaft position sensor? Mario
Dear Mario: Yes, it could be the crankshaft sensor, along with a number of other possibilities. When we have start-stop issues that are hard to duplicate, we drive the car with test equipment connected or let the customer take the car with the test scan tool connected. I would even suggest having the dealer hook-up a fuel pressure gauge, too. Then when your vehicle stops, push on the scan recorder. It will record events before and after the stall, as well as when you are trying to restart the engine.
Dear Doctor: There's an annoying musty scent in my 1999 Isuzu Amigo soft top 4x4. I noticed some moisture underneath the floor mats. Everything else is dry in the truck. Is this just a circulation issue in the wintertime, since I have the soft top instead of a hardtop? I've had the truck for three years and this is the first time I've noticed this. How can I correct it? Ennio
Dear Ennio: Water is leaking into the vehicle. We use a garden hose without the nozzle and let the water run over the affected area. If your vehicle has carpeting it should be removed for cleaning and the leak repaired before it is re-installed. I recommend you go to a body shop to help locate the leak and make the repair.
Dear Doctor: My 2009 Nissan Rogue was involved in a car accident, resulting in damage to the front passenger side. It was at the repair shop for over a month. At the next regular oil change at the dealership the technician noticed a coolant leak. I brought it back to the collision repair shop and they changed and tightened the clamp. At the oil change, again, there was leaking, though less than before. They also noticed the front passenger tire was worn and needed to be replaced. I had also got a flat tire a few months earlier involving the right front tire. Now the dealer says he wants to try Nissan tubing, as the collision repair did not use a Nissan replacement. Any suggestions? Diveda
Dear Diveda: For your coolant leak, a coolant system pressure test should be performed. It's possible that the clamp is still not tight enough. As for tire wear, a check of the wheel alignment should be done before any tires are replaced. The correct air pressure is another factor. Having a plug repair in the tire should not cause any unusual tire wear. If your Rogue is all-wheel-drive, then your tire life will naturally be less than that of a front-drive only vehicle.
Dear Doctor: I own a 1995 Mercury Sable with 116,000 miles. At my mechanic's suggestion, I had the rear shocks replaced. Since then the rear suspension has become extremely noisy, sounding like it's bottoming-out. A second set of new shocks was installed at no change. This condition did not exist before. My mechanic test drove the Mercury and agrees there is a problem, but he can't find it. Do you have any suggestions? John
Dear John: Since the noise was not there prior to the rear shock or rear strut installation and a second set replacement was made, we do know the problem is suspension-related. An often-overlooked area is the rear sway bar bushings and links. Other sources of noise are rear brake calipers. To check for rear brake caliper noise drive over road bumps and lightly apply the brakes and see if the noise lessens. Upper strut mounts, even an exhaust pipe hitting the rear cross section, will also cause noises. Have a different technician road test and also have the car checked on a drive-on style lift.
Dear Doctor: I own a 2004 Honda Odyssey with 90,000 miles, which runs great and the transmission does not have a problem. The dealership serviced the transmission at 60,000 miles. When he was done I found out that he only drained 3 quarts. I asked him at $80 he can only drain 3 quarts and he said yes. The last time I was at the dealer he said my fluid had changed color slightly and to keep an eye on it. I had someone drive me to the airport and he remarked the car had plenty of power when he picked me up. I noticed he was driving in D2 instead of overdrive at 75 mph. I suspect the tranny ran a little hot. Can I fully drain fluid to replace it? Do you think the tranny was damaged? Larry
Dear Larry: A fluid drain on the Odyssey, and other Honda vehicles, requires 3 to 4 quarts when the drain plug is removed. We handle a fluid change in one of two ways at the customer's request. We will either use a fluid flush machine with Honda fluid or we will change the fluid three times. Many Honda drivers make the same gearshift error, as your friend did. However, this will not cause a problem. Regarding that color change in the fluid, we find that the transmission is the weak link on Honda vehicles. -- Junior Damato, Motor Matters
Junior Damato is an ASE-certified Master Technician.
E-mail questions to firstname.lastname@example.org