1999 Silverado Squealing

[sierralindsay]

I have a 1999 Chevy Silverado with a 5.3L v8. Recently it started squealing wicked bad and I thought it was the idler pulley. I replaced that, but the squealing continued so I next replaced the serpentine belt and the tensioner pulley. The squealing stopped for a couple days, but came back. Once in a while randomly, the squealing will stop, but it always comes back. This is becoming seriously irritating. Does anybody know what it could be? I also have already checked the alternator just in case. Thanks for any help!

 

[Chuzz]

How did you check the alternator? Is sure sounds like it's a defective pulley, and most times that points to an alternator, but can be a power steering pump or even water pump sometimes. Go to your local Autozone, Advance or O'Reillys and have them load test the charging system for you. If it's pulley related, the load on the system should make something start squealing. If it doesn't show up, perhaps you just need to remove your belts and give all of the pulleys a good cleaning.

 

[zora]

Does the sound occur at idle? If so take a rubber hose, hold one end against your ear, and move the other end to the various pulleys the belt rotates around to isolate the source of the sound.