Stopping Jeep Cherokee Belt Squeal

May 22, 2005 12:44 PM

My 1989 Jeep Cherokee's serpentine belt is squealing horrifically. Nothing I have done will make it stop for longer than a few minutes.

My Jeep, with the 4.0l inline-6 engine, emits a terrible squealing noise whenever the revs get up above an idle, and a steady chirping sound at idle. The squealing increases in pitch and volume as the engine revs go up.
In the last few months I have replaced the water pump, idler pulley and the alternator is new. The serpentine belt was replaced at the same time as the water pump.
Spraying the tiniest amount of lubricant (of any sort - WD-40, silicone lube, white grease) on the belt will stop the noise temporarily, but it usually starts again by the time I get the hood closed and get back in the car.
It is not a belt tension issue as I have checked that the belt tension is correct, and experimented with tighter/looser tensions.
It doesn't seem to be having any detrimental effect on the operation of the engine, but it is simply becoming increasingly embarassing to drive around in with the constant noise.
I have read in places that the harmonic balancer may be the culprit. Before I shell out the cash and scraped knuckles involved with replacing the thing, does anybody have any other insights of suggestions as to what may be causing the squealing noise?

posted by davey_darling to travel & transportation (9 comments total)

don't put petroleum based stuff on the belt as it plays hobbs with rubber. try touching a bar of soap to the belt(while the engine runs) inside and out, and see if that helps
posted by hortense at 1:03 PM on May 22, 2005

I'm having a similar issue with my 1997 Grand Prix. It's not quite as bad as yours, but the whining/sqealing does get worse as I rev the engine. I just replaced the belt tensioner and that didn't do anything for it.
posted by BradNelson at 1:04 PM on May 22, 2005

"Using a spray bottle filled with water, mist the belt lightly. If the noise level recedes for several seconds, then returns louder, a misalignment problem is likely. If the noise immediately increases after the belt is sprayed, slipping is likely... If the water spray test is inconclusive, or not successful at diagnosing the problem, attempt to remove the noisy belt and re-install it so that the belt runs in the opposite direction. Because misalignment noise is influenced by the direction of misalign ment in the drive, flipping the belt around in this manner will eliminate or significantly diminish (temporarily) any noise caused by drive misalignment. If the noise remains unchanged, the problem is not likely related to drive alignment... Also, look for replaced drive components, such as a rebuilt alternator, which may have been improperly installed resulting in pulley misalignment." (Source.)

And I second the advice to keep oil and grease away from your belts. That causes glazing and slipping and squealing, oh my!
posted by naomi at 1:59 PM on May 22, 2005

Really, don't oil belts. It's the squeaky wheel that gets the grease, not the squeayk belt. It may be that the lubricants have worsened the noise. There are belt-dressings intended to make belts stop slipping, but they are more like adhesives than lubricants.

It is also possible that the noise is not the belt at all, but a bearing in one of those replaced components, or a misalignment due to the water pump's mismanufacture. I have spent hours in zero-degree weather installing a rebuilt water pump, only to see it pump antifreeze onto the ground. Sometimes all they rebuild is the paint.
posted by Kirth Gerson at 3:16 PM on May 22, 2005

Google Groups to the rescue.
posted by weapons-grade pandemonium at 5:22 PM on May 22, 2005

Sometimes the surfaces that mate to the belt get polished as well, to the point where belts slip. I had horrible sqealing troubles with my 96 F-150 until I sprung for the (twice as expensive) Goodyear Gatorback. Not a peep in the 3 years since- absoulutely silent. Cheap serpentine belts are trouble waiting to happen.
posted by pjern at 9:56 PM on May 22, 2005

Although not usually a squealing sound, alternators can make strange sounds when they are dying. If your 89 Cherokee has never had the alternator replaced it could be time. I had to do it last fall in my 89 Blazer. If you have tools, it's an easy job to do yourself and save alot of money.

Do you have any friends with car knowledge near by? It can be hard to diagnose over the internet. You might be able to run the car with the hood open and carefully listen to pinpoint the noise.
posted by 6550 at 10:23 PM on May 22, 2005

Alternators can also chew through a belt as they go, which can cause squealing in addition to dying alternator noises.

I've had that happen more times than I care to admit, since I never get into the shop until the car stops moving.
posted by Kellydamnit at 7:54 AM on May 23, 2005

Update: The squealing was not coming from the belt per se, but from the harmonic balancer. It seems the rubber in the balancer had degraded to the point that the outer ring shifted back and was rubbing against the timing chain cover.

I replaced the harmonic balancer and the problem disappeared completely.
posted by davey_darling at 8:50 PM on November 30, 2005