Reader Question: We bought a 2000 Pontiac Grand Prix a couple of weeks ago. When we first started the car, it made a squealing noise, but the man we bought it from sprayed WD-40 on the drive belt and it stopped.
Well, two weeks, one new belt, one new water pump, and one new pulley later, it is still squealing when you accelerate. It does not squeal when it is idling.
Do you have any idea or suggestion as to what may be causing this squealing noise?
Did you replace the belt tensioner? I would also inspect the alignment of the pulleys to make sure they are all in a straight line and the belt is not cocked eyed. Check the new belt for abnormal wear on the sides as well which would indicate that a pulley is not aligned properly and rubbing the side of the belt.
I would also triple check the belt part number! Make sure the auto parts guys check for any foot notes for optional equipment or origin of manufacture. I would visit your local GM dealership parts department and buy one of their belts or if in doubt of the proper belt length, try buying a slightly shorter length belt.
Also, make sure ALL the pulleys are using the same number of grooves as the belt. I have seen people install an alternator that had less grooves in the pulley as the belt had, so the belt never really fit the alternator properly.
Take your time, start with the belt part number, and slowly work your way through the rest of my suggestions. I would bet this is something simple that is just being overlooked.