What would cause a squealing sound if it is not the brakes or belts?

I have THE answer. You have defective bearings in your Distributor shaft. It is a $300 part. I spent a few hundred dollars and with the help of two very persistent mechanics they found the problem. I know what you are going through. It sounds like a belt. The squealing may even cause your van to shut off, especially when idling. If this is the case, be sure that it is the distributor shaft.

basil

The type of vehicle and more information is needed to answer this question, unless you have a parts "shotgun".

What kind of car? engine size? If there is a tensioner and it is weak, it help the belt to squeal. Spray anything wet on the belt -- does the noise stop? If you e the idle without moving will the noise start? Need more info.

This could also be caused by power steering system. Check for leaking tank, low fluid etc.

Have you checked the wheel bearings?

If its not your belts and you got them replaced its possible that your water pump is starting to go.

If you did not get the noise fixed yet, you might want to check on the pulleys where the drive belt is installed and/or the water pump. Pulleys make a high pitch noise when they are worn out either when you first start the engine or during acceleration. Water pump also makes the same noise. Check the little hole above or under the pump, if there is a sign of water/coolant coming out of the hole, your water pump needs a replacement. I hope this can help you.

could also be worth considering your "clutch, thrust bearing", sounds painful I know, not a major job though in the right hands.

In addition to the above, Tires could, PCV valve if not replaced properly on certain engines, alternater.

if its from the rear it could be a fuel pump if your car is efi

Alternator

http://www.autozone.com/servlet/UiBroker?UseCase=S001&UserAction=viewSimpleDiagInfo&Parameters=info answer could be bearings wearing out in alternator, a/d compressor,or any other pulleywheel on engine.could also be dry thrust bearing in clutch.need more information, does the noise go away when engine is reved does it get worse if you use a/c,does it happen when stationary or when moving

Flywheel

it could be the cylanders

or you could have a mouse in your car.

i recommend you get a cat

Suzanne:

My daughter's car had this problem

It ws in deed the distributer. The price wasn't too bad from autozone. $175 remanufactured plus core charge. The local mechanic charge $20 to install it

Parisa:

I agree with the first answer put down, i have an old car but brakes n wheels seemed fine, there was a problem with the cv shaft, it will cost between 300-400 to fix, i got it reconditioned and my care doesnt make a sound when i brake