Niagara Gazette — A few questions and answers this week:
JOHN FROM NIAGARA FALLS: Help! When my car is parked, the engine temperature increases to a normal temperature. When the car starts moving, the temperature drops. What’s happening and what can I do about it?
TOM: It’s important to give me the year, make and model of your car when seeking information. That said, check the coolant level. It is probably low and that’s the reason for loss of heat when driving. When an air bubble gets into the system, it travels throughout the system while the engine is in operation causing loss of heat and, in worse case scenarios, overheating. Another possible cause of this problem is a bad thermostat that is stuck in the wide-open position, offering no resistance in the system. Consequently, there is no time for the coolant to absorb heat from the cylinders and carry it to the heater core where the heat is transferred into the vehicle cabin.
JOHN FROM ACKWORTH, IOWA: I own a ‘99 Buick Park Ave with110, 000 miles (automatic transmission). There is a buzzing sound up front when driving. This sound persists when I select neutral and speed up the engine with no change in sound frequency. When I steer left it stops; going to the right it continues. Is this a wheel-bearing problem?
TOM: Based on your description of the problem, I would say that yes, you have a bad wheel bearing on the right front side. What is happening when you turn left: You relieve pressure on the bearing by shifting the vehicle’s weight up and off the bad bearing. When you turn right, you intensify the noise by shifting vehicle weight downward onto the bad bearing causing it to growl (or buzz, as you call it). A good tech can put the car on a lift and pinpoint which bearing is bad with an electronic listening device.