I am posting this for my buddy who is very frustrated. He has a 2004 MC with a 3.8 nonsupercharged. He has developed a very loud whining noise coming from the belt side of the motor but only after the car gets hot and only at idle.

He has replaced the water pump assembly, new alternator, new tensioner pulley, new tensioner assembly, and a new belt.

After all of this being done over a few weeks the problem is still there. I asked him the other night if it makes the noise with the belt off and at the time he didnt know so that night he tried my suggestion and got the car hot so the problem was acting up parked the car and removed the belt and it was still whining still only at idle.

His power steering fluid is full as well.

also when this whining is going on when he takes his foot of the gas and applies the brake there is a chirp noise and same goes when going from brake to gas.

He is very frustrated at this point and we have looked over the net but cant find anyone with this problem, any help would be great, thanks in advance.

 

It may be possible that it is the AC bearing, or the power steering bearing (Although you said the power steering fluid is full, I'm just throwing some ideas out there). I am having a similar issue with my MC and I have to troubleshoot this weekend. If it's the AC unit I'm just going to do an AC delete because I don't have the cash to replace it.