LS2 engine squeal

[69camaro72]

Any suggestions on what could be causing a high pitch engine squeal? Only happens after car is warm and when idling down from acceleration. We have switched tensioners, pulleys, belt, ac bracket and just now put the new alternator pulley and clutch on and that didn't fix it. Only thing left that we haven't switched out is the water pump and power steering pulley. Anybody else have an issue like this?

[LUV2XLR8]

how bout oil pump?... check your pressure?

[69camaro72]

Yes oil pressure is fine. :(

[LUV2XLR8]

i would say its a bearing of some sort.....inclination only when it's hot..... take of the pulley on the water pump... rotate it by hand see if you can feel any low spots on the bearing when you twist it... or see if you can rock it back and forth ..up and down..

[69camaro72]

I ended up putting a new water pump on it to no avail. However, we found the problem last night. It was the frest air intake pvc line. Took that valve off and it ran and sounded just like it should! I can't tell you what a relief it is to know it's fixed, but man what an ordeal getting there. Thanks for your suggestions luv2xlr8!

[dontlifttoshift]

Mine does that, too!

What valve did you remove? I don't have any valves in my system.

[69camaro72]

To be more specific, my mechanic said it was crank case ventilation - engine wasn't getting fresh air. Hope this helps. I can take picture if that would help you.

[dontlifttoshift]

Hmmm, LS2 there is the hose that runs front the valley cover to the throttle body......that's the dirty side. Then your valve cover(s) should be vented to clean air. I ran -6 hoses to my intake tube and that is where they whistle.......I tell everyone its the turbo. Point being, there are no valves like there used to be. Just calibrated vacuum leaks.

[LUV2XLR8]

NICE!... glad you got it figured out... sometimes the easiest things can be the biggest pain!