I just changed the accessory belt & tensioner, along with the A/C belt & tensioner and I still have an intermittent squeal only at about 1250-1400 RPM. WTF?! It doesn't matter whether I have the A/C on or not. The car is a 1999 FRC 6M w/ about 49K on it. Maybe it's time for an U/D pulley? BTW, who makes the best one for a daily driver...I have stock electrical accessories.

 

I have the same issue. I replaced the belts with goodyear gatorbacks and all of the squeaks went away except that 1200-1400 rpm range. It sounds to me like a hiss or squeal from the airbox? It sure is annoying everytime I hear it.

 

E-T posted a great summary of how to fix belt squeal. I know he doesn't mind me re-posting it.

"You have two belt systems on your car. One is the drive belt system, the other is the air conditioner belt system. The drive belt system consists of the serpentine belt, the power steering pump, alternator/gen, water pump, harmonic balancer, idler pulley, belt auto-tensioner pulley. The AC belt system consists of the compressor, harmonic balancer, idler pulley, belt auto-tensioner pulley.

First thing you need to do is isolate which system is squeaking. This can be done by releasing tension on the drive belt tensioner and removing the serpentine belt. This is the outboard belt of the two belt systems. If the squeak goes away, then it’s the belt or a component of the drive system.

If the squeak is still there, then it’s a component of the ac belt system.
To verify this, release the belt tension from the tensioner and remove the belt. If the squeak goes away, then it’s a component of the ac belt system.

A common problem is the belt tensioner on either system but verifying which system is at fault is the proper procedure.

You could replace both belts, but you may still have the squeak. If you want to find the culprit, isolate the system, then spray the belt of the offending system and see if the squeak goes away. Try to stay away from the idler and tensioner while spraying. I find that belt dressing may be good to identify a belt problem, but it is a temporary fix at best.

The real problem has been the tensioner and the idler. Both of these components have a sealed bearing which has been know to dry up or redirect the grease away from the bearing, thus causing the squeak.

If you find that a belt change does not correct the problem, then a change of both the idler and tensioner pulley is in order. If you just change the idler or the tensioner alone, it will cause the other component to go bad in a month or so. This has been the case with many members. There was a change made to the dusts seals to help correct this problem in newer C5's. Lots of tensioner and idler pulleys have been identified as a problem and it can affect either system. One is not more prevalent than the other. So find out which system is squeaking first, in the drive belt system. It could also be the bearing of the alternator, power steering pump, or water pump too, but these are less probable.

I hope this makes things a little clearer"

Courtesy of E-T

 

It just may have a little dirt or grease from the installation process.

I did this with the engine running and the squeak went away quickly.

 

I had tow problems. I originally had a squeak at 1700. But I was not really alarmed about that. Then I got a consistent squeak. First I removed the AC belt and it eliminated the consistent problem. I changed the AC belt tensionner and idler + the AC accessory belt tensionner. The Consistent squeak was gone. But I still had the 1700 RMP squeak. I replaced the Drive belt idler (below the alternator) and every thing is fine now.

 

Same thing here except it WENT AWAY after new belts a water pump and 2 new tensioners. Comes back OCCASIONALLY at low speeds.

Dealer was stumped.

So am I.

 

Your stumped????? did you read post # 3 in this thread... did your dealer replace both tensioners and both idlers?????? that four bearings...
Did he do the prescribed procedure to identify which component was at fault???? this isn't brain surgery...

 

.... ...but maybe it was the door hinge squeaking and the dealer ran out of grease ...
BTW...thanks for the PM Bill...didn't realize the bottom feeders were still out there STILL with a grudge

 

There was a TSB for an accessory drive squeak for the 1997 - 1999 C5's with the LS1 engine. You can view it here: http://corvetteactioncenter.com/kb/q....php?qstId=258

Replacement of the idler pulley specified in the TSB eliminated the squeak on my 1999 C5. (There are two idler pulleys - the defective one is located under the alternator). Good luck.