Expert: Mike Evans - 11/4/2009

Question
hi, i have a 2000 chevy cavalier and i'm worried about what is wrong. when i push on the gas pedal there is a loud whining noise but only when i push on the gas. i looked while someone else did it and it looked like a pulley was loose but i could be wrong. and idea what it could be?

Answer
    Is this while you're going down the road or sitting still?  If it's sitting still, then one of the bearings in one of the pulleys is bad.  It is most likely the idler pulley, but there are bearings in the alternator, water pump, A/C compressor, and power steering pump as well.  If you can see the pulley moving in and out while the engine is running, then you need to get it fixed immediately.  The bearings in all of these can be changed, but most mechanics won't attempt it and would recommend replacement of the whole unit.  I would agree with them.  If it is doing this while you are moving down the road, though, it is probably the transmission.  The engine speed doesn't change when in motion, unless the transmission shifts gears, but the load on the transmission can do all sorts of things.