re-occuring squeaky drive belt
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
It could be more than just a belt
Heres agreat How To from E-T which may explain it better and help you troubleshoot
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
Heres agreat How To from E-T which may explain it better and help you troubleshoot
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
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
the tensioner pulleys are known to fail.
When the belts are off, had spin each pully.
It should spin freely and smoothly without any wobble.
It it wobbles or feels "gritty" or binds in any way, you hav efound your culprit.
Remember to check both systems.
In my case it was the A/C condensor clutch.....
When the belts are off, had spin each pully.
It should spin freely and smoothly without any wobble.
It it wobbles or feels "gritty" or binds in any way, you hav efound your culprit.
Remember to check both systems.
In my case it was the A/C condensor clutch.....
4th Gear
Joined: Mar 2006
Posts: 4
Likes: 0
the tensioner pulleys are known to fail.
When the belts are off, had spin each pully.
It should spin freely and smoothly without any wobble.
It it wobbles or feels "gritty" or binds in any way, you hav efound your culprit.
Remember to check both systems.
In my case it was the A/C condensor clutch.....
When the belts are off, had spin each pully.
It should spin freely and smoothly without any wobble.
It it wobbles or feels "gritty" or binds in any way, you hav efound your culprit.
Remember to check both systems.
In my case it was the A/C condensor clutch.....
email is now alberstoner@bellsouth.net can you help?
4th Gear
Joined: Mar 2006
Posts: 4
Likes: 0
I have been chasing this problem for a year. I changed all idelers and tensioners. This past weekend I paid $170.00 for a new alternator. I still got the squeel. After it warms up a bit the squeel stops at idle but is there above 1500 RPM. I don't know what to do next.
email is now alberstoner@bellsouth.net can you help?
email is now alberstoner@bellsouth.net can you help?
the tensioner pulleys are known to fail.
When the belts are off, had spin each pully.
It should spin freely and smoothly without any wobble.
It it wobbles or feels "gritty" or binds in any way, you hav efound your culprit.
Remember to check both systems.
In my case it was the A/C condensor clutch.....
When the belts are off, had spin each pully.
It should spin freely and smoothly without any wobble.
It it wobbles or feels "gritty" or binds in any way, you hav efound your culprit.
Remember to check both systems.
In my case it was the A/C condensor clutch.....
Race Director
Joined: May 2000
Posts: 14,542
Likes: 5
1. Check the harmonic balancer -- if it wobbles replace it.
2. Also replace both belts; emphasis on both.
3. If you still have the squeal, replace the idler pulley and tensioner.
Guaranteed that will cure it.
Don't waste your time on belt dressing.
Goodyear is OK, Gates work just as well.
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