Very squeaky belts
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
Heres a great description of the belts and pulley systems posted by E-T a while ago.
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.
I hope this makes things a little clearer
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.
I hope this makes things a little clearer
Racer
Joined: Feb 2003
Posts: 418
Likes: 28
From: Evansville IN
Wish I'd read to clean the pulleys sooner! I just changed the harmonic damper $180.00, new tensioner with idler $65.00, new idler $20.00, new belt $20.00, (Gates because I couldn't find a Gatorback in stock anywhere). After all this the belt still squaked like hell from about 20 seconds after startup until I shut it off.
I CLEANED THE FREAKEN DIRT OUT OF THE POWER STEERING PULLEY GROOVES AND THE NOISE IS GONE!
Now I remember about a week after I bought it I had the hood open and apparently one of us, (my wife or me) had parked on something like very fine powered dirt or something, anyway, it was all over in the engine compartment. Soon after guess what, belt started squeal. Didn't put 2 and 2 together until about an hour ago! Sometimes I'm slow..., well, a lot of times I guess.
I CLEANED THE FREAKEN DIRT OUT OF THE POWER STEERING PULLEY GROOVES AND THE NOISE IS GONE!
Now I remember about a week after I bought it I had the hood open and apparently one of us, (my wife or me) had parked on something like very fine powered dirt or something, anyway, it was all over in the engine compartment. Soon after guess what, belt started squeal. Didn't put 2 and 2 together until about an hour ago! Sometimes I'm slow..., well, a lot of times I guess.
