Dear Doctor: I own a 2005 Hyundai Tucson with 85,000 miles and a 2009 Sonata with 27,000 miles. I recently found a case of synthetic motor oil that is about 10 years old, uncontaminated and unopened. Is it still usable? With such limited driving each year, can I consider changing my oil only once or twice a year?
Dear RC: The synthetic oil should still be good. You need to check the oil requirement in the owners manuals and check the oil rating on the oil container. I would think that the oil should be good for these vehicles, however I want you to verify the specifications before you use it.
Dear Doctor: I plan to buy a 2003 Volkswagen Passat turbocharged four-cylinder. Can the turbo be disconnected or taken off without affecting the engine performance? If so, can I use regular gasoline?
Dear Bob: The engine is designed for the forced air induction from the turbocharger and without it the engine would need to be retrofitted with new higher compression pistons, fuel injectors, computer and wire harness -- over a $5,000 investment. There is no reason to eliminate the turbocharger; they are much improved from years ago. The only time the turbocharger does add pressure/boost is when the accelerator is pushed half way or more. Turbocharged engines do need premium grade gasoline to make maximum power, and full synthetic oil to properly lubricate the turbocharger from its heat.
Dear Doctor: I have a 2012 Cadillac CTS. When raining or snowing and usually remote starting, an unpleasant odor emits from the vent system. The a/c button is on when remote starting. Turn off the a/c and the odor is gone in a few minutes. The odor will return if rain or snow begins. The dealer has changed the cabin filter twice, coated the coil and cleaned the duct system. The odor smells like mildew. The odor is not present for two weeks following service, but returns. This has been going on for 18 months. The dealer has had the car under all weather conditions, and says that "the vehicle is operating within spec".
Dear Victor: A mildew odor indicates old moisture. The cabin filters are treated with a charcoal substance that helps eliminate odors. There are some aftermarket chemicals that can be used to help eliminate mildew odors, too. One of the main reasons new vehicles sometimes have this mildew smell is because the interiors seal tight with very little fresh air coming in and some ventilation systems recirculate the air and do not bring in fresh air. Make sure there is no water leaking into the interior and heater box and make sure the heater box drain is not plugged up.
Dear Doctor: I purchased a 2009 Lincoln MKS in mint condition in January. It just reached 60,000 miles. I assumed I would take it in for a transmission service at this mileage, since it has never had one. However, according to the maintenance schedule, it recommends 150,000 miles for a transmission service and the fluid changed. Is this possible?
Dear Joseph: I service all major makes and models and see the manuals that recommend transmission fluid service internals of 100,000 or more. What I do is take a look at the vehicle's use and fluid condition -- and in 90 percent of the cases will get the transmission fluid changed. I always use the factory transmission fluid on all vehicles. I will also say that today's multi-speed and CVT automatic transmissions have their share of failure. In my opinion, clean fluid can only help prevent failure.
Dear Doctor: On my 2009 Pontiac Vibe, the "VSC OFF" indicator light began flashing and the ABS, Traction Control, and Brake indicators were on steadily. The error code showed PO442 and the shop installed a new Evaporation Canister. About a month later all those indicators started showing again, but this time it happened intermittently. What should I do?
Dear Frank: The p0442 code is for the evap system, which has no connection with Vehicle Stability Control and ABS systems. In some cases there could be history of codes that can be retrieved from the computer. But if no codes are in memory, then the vehicle will have to be checked (scanned) with the lights on. A false signal from the anti-lock brake system will turn the VSC or ABS lights on, as well as fault code from the computer for any reason. A professional technician who uses the services of both Alldata and Identifix will be able to research the system and find the problem.