Dear Doctor: We had the dealer in Florida put a new water pump and computer in my 1997 Pontiac Grand Prix (78,000 miles). My son then drove the car to New York. Now he can barely drive around the block without it overheating. He removed the water pump, thermostat, hoses, and radiator to make sure they were not clogged. All checked out fine. What is causing the overheating? John
Dear John: If there is no faulty gauge reading, then a simple (and often overlooked) step is to check the cooling system for any hydrocarbons (exhaust gases) that might be caused by a leaking cylinder head or head gasket. If there are no hydrocarbon readings from the cooling system, then a circulation test will need to be performed.
Dear Doctor: We had the brakes resurfaced on our 2003 Nissan Altima. Now the brakes consistently make a noise when releasing the brake pedal. It seems to be emanating under the car somewhere between the seats where the console box is located. The dealer said this is a normal noise. What do you think? Mitch
Dear Mitch: The noise that your Nissan Altima is experiencing sounds like it’s coming from the park interlock safety solenoid. The solenoid unlocks and allows the transmission shift lever to be moved out of park. Some vehicles are louder than others. If this is the source of the noise, then yes, it is normal.
Dear Doctor: I have a 2000 Toyota Avalon with a V-6 and 100,000 miles on it. After taking a 360-mile trip the engine developed a loud buzzing noise, which goes away after the engine warms up. My mechanic says the cam sprockets need to be replaced, but to hold off until valve work is necessary. I read something about the Avalons having trouble with a VBCI oil line coming loose and causing a loud engine noise. I don’t care to take the car to the dealer. What would you advise? Jim
Dear Jim: The camshaft sprocket is driven by a rubber-timing belt on this vehicle. There is an oil control valve that controls valve timing on the Avalon. You should not hesitate to go to the dealer with this problem. With 100,000 miles on the vehicle I think that a small repair now could save big money later.
Dear Doctor: I own a 1989 Ford Bronco II with the 2.9-liter V-6 and automatic transmission. I have a rebuilt engine with 90,000 miles. When the “check engine” light comes on the engine will speed up. When the “check engine” light goes out the engine speed returns to normal. What’s causing this to happen? Bill
Dear Bill: The diagnosis will require a technician who has access to a professional full-service scan tool.