I have a noisy belt. It looks like the harmonic balancer is shaking a bit. Could it be the harmonic balancer is going bad? Any other ideas?

 

Main belt? Mine was the ac belt....took it off, no chirp, checked all tensioners and pulleys, then changed the belt. Chip gone.

 

Yes it could this is a common problem with the C5. A real pain to change.

 

mine was the AC belt also

 

take off the AC belt and run the car... no chirp problem is in AC belt system.... hand spin the pulleys. they should spin freely. If they stop and or feel gritty that pulley is the culprit.... if all on this system are fine.... the problen is the AC clutch

If there is still a chirp then the problem is on the mail serpentine.
Remove the belt... again hand spin and determine if one is bad... if not then it is the harmonic balancer....

IF yours is wobbling.... it is quite possibly the issue as an earlier post stated, they go bad on C5's

 

ET who was one of the C5 design engineers posted a great summary of the system and I’ve copied it below. Run through that procedure to identify where the problem lies. If it’s a belt that’s good news and is fairly straight forward once you work out the technique.

Here’s a pic to identify the components.



Belt Squeal Courtesy E-T

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.

 

If you are going to replace the belt, get a Gatorback. I replaced all the pulleys on the front of the engine and still had squeak. Threw on a Gatorback, all silent. If you have a little balancer wiggle it has some side to side wiggle to smooth out everything.


Chris

 

hard to change the belt? took me like 5 min just needed the wrench to loosen the one pulley and it was easy also changed mine and the belt is now silent

 

I had that problem a few years ago, it was the tensioner and a belt replacement, cost a couple hundred to fix.

 

JUST CHANGED MINE
THEY ARE RATTED FOR 6500RPM AND WILL FAIL .COMMON PROBLEM!!
YES RACK HAS TO COME OUT,SUCKS SO PUT IN A GOOD ONE.25% UNDER DRIVE IS GIVING ME TROUBLE WITH ALTERNATOR AND WATER PUMP.
HAVE FUN
MIKE

 

I've had mine and two other friends vets getting noisy, all three had 60,000+ miles on them. New belts didn't help. I changed all the idlers and tensioners and solved the problem on all three. Not too difficult to do. Putting the belt on the AC was the hardest thing to do. Do a search on the forum, there are posts about replacing the pulleys. This forum is great for these items/questions.

 

the tensioners start to lean towards the radiator and that causes the belt to run ever-so-slightly crooked across the pulley. That makes the squeak.