Whining noise coming from engine

[drew2]

I have taken my 02 Trailblazer into 3 different shops now and have not been able to get a straight answer. There is a whining noise coming from my engine bay, sounds like a bad bearing. The shops have told me that the idler pulley isn't going bad and actually use got a new one to make sure. None of the other pulleys are bad, and everything is just fine. I am thinking that it could possibly be something with the water pump but I am not sure and don't want to drop the money if it won't fix the problem. Any advice would be greatly appreciated. Thanks!!

[hilljb]

I'd remove the serpentine belt and start it up... not for long, but long enough to see if the noise goes away.

Otherwise, assuming this is present at idle, you can use a longish length of tubing, placing one end at your ear and using the other to poke around in the engine bay to try to pinpoint exactly where the noise is coming from.

[KingBird]

My water pump made a loud squeaking noise when it went bad.

I jerked the belt to replace the idler pulley and that's when I noticed that the water pump pulley had play.

[Trail X]

Be sure to check your tensioner pulley. It's pretty similar to the idler when it goes bad as I recall.

[ElRey]

I know this is kind of old, but I had a bad whining issue in my 07. The idler pulley and tensioner pulley are technically the same part. I replaced both, took all of 30 min and $30 at autozone. Problem gone...and I feel like my ride got back a few more HP!