Q: I have a 2012 Hyundai Santa Fe AWD that I use for towing a light boat. Recently, I found myself parked on a steep grade and tried to back up. I put my left foot on the brake pedal to hold the vehicle from rolling forward, and put my right foot gently on the gas pedal. The gas pedal did not react. If I removed my foot from the brake, the vehicle would lurch backward with tires spinning. My Hyundai dealer said this is normal behavior and suggested I do not park on hills. Really?
— T.K., Crystal Lake, Ill.
A: Really. Beginning with the 2012 model year, Hyundai installed a brake-throttle override on all its vehicles, across the board. In many instances of unintended acceleration, it was found that drivers stomped on both the brake and accelerator. With the override system, hitting the brake disables the throttle. NHTSA has called for all vehicle manufactures to begin equipping new vehicles with this technology.
Q: Just got done reading your article on tire pressure monitors. You claim they should last 10 years. I have replaced three sensors on my 2009 Dodge Journey in the last four years. Problem is they corrode around the stem or the retainer ring corrodes and breaks. Is this normal or should I have been reporting this to Dodge or NHTSA? Fortunately, they failed while at home and not on the highway, which could have been tragic.
— J.U., Downers Grove, Ill.
A: What kind of valve caps are you using? It matters. If you put a steel or chrome cap on an aluminum valve stem, a galvanic reaction causes corrosion. In some cases, the cap seizes to the stem. In other cases, the stem and/or attaching nut break. Many custom aftermarket caps are not properly nickel plated, so they are a major problem. Stick with plastic or rubber caps.
Q: You replied to a question in today’s (Jan. 18) Motormouth column about the wisdom of starting a car in bitter cold weather. Your reply was that the energy required to crank the engine was probably more than would be replaced when running the car for a few minutes. I think there is an even more important reason. When the exhaust system and catalytic converter in your car are cold, the moisture and combustion products condense in this system and, over time, corrode expensive parts. I think the exhaust systems on modern cars are much more resistant to this corrosion than they were a few years back and believe that the practice will shorten the life of exhaust system components.
— M.L., Libertyville, Ill.
A: Stainless steel is extensively used in today’s exhaust systems, but it is not immune to damage. Mufflers are currently the weakest link. You make a good point.
Q: Due to a carwash incident years ago I always take my back wiper off my cars before running the car through the local carwash. It reminds me of the fact that rear wiper blades on most cars are not as efficient as the front wipers. Is this a physics issue or is the rear wiper system an afterthought for most car manufacturers?
— R.F., Warrenville, Ill.
A: It is a physics issue. At the back of the vehicle there is a bit of negative air pressure. In other words, a partial vacuum. This is the same principle that causes fallen leaves to follow a vehicle that passes over them. In the front, there is positive air pressure, but when it becomes too great, it lifts the wipers from the glass. Beam style wipers are a godsend.
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