I'm just going to start off with the obvious. It's not the supercharger's whine right?

 

^ was wondering the same.

How long have you owned the car?

 

Ive owned the car for over 2 years now and this problem only started within the last couple months. Its a very loud whine noise.

 

Blow up a balloon and stretch the mouth of it while you let the air out. That's about the closest description of it that I can think of. Could it possibly be a vacum leak?

 

PCV valve?

 

It is a higher pitch sound than what normal would be. It gets louder the more gas you apply.

 

could it be something internal in the supercharger?

 

Idler pulley.

Bearings on the inside could be wearing out/out of bearing grease and causing the noise.

 

PCV on pass side upper intake I believe....doesn't sound like a supercharger bearing...you should be able to tell the difference.

 

So i changed the pcv valve and found a bad s.c. idler [grooved one]. It didn't help. With the s.c. belt off the noise was still there but very faint. The belts don't look to bad maybe a little glaze. Suppose i'll check motor pulleys and try new belts. Maybe belts are slipping? Thanks for all the ideas; any more?

 

Have you asked at www.GrandPrixForums.net , www.ClubGP.com , www.LS1Tech.com , & www.PontiacBonnevilleClub.com ? The more the merrier.

 

I have heard the serpentine belt tension idler make a whine noise when the bearings are shot. Have you checked this?