Loud belt squeal

[Vettepirate]

Alright. Some of you might remember me having this problem for some time as I've made a thread on it before.

I'm now embarassed to drive my car, which is shameful. It just squeals so loud I keep being reminded of a rusty old beater whose owner just doesn't care that his car sounds like a pen full of piglets.

I've replaced both the Idler Pulley and the tensioner pulley and the problem persists. The only change I saw is that the squealing noise changed a bit when i replaced the tensioner pulley. Whether this was the belt adapting to the new piece or the belt alignment changing is anyone's guess.

I'm thinking maybe there is a serious alignment issue with the belt? I can't replace every single pulley on the engine but it seems I may have no choice. Could my problem be caused by a wobbly pulley somewhere? I might resign myself to changing the belt a few times a year because it seems to solve the problem in the short term until it starts again.

I hear the Gatorbacks are good, I may try one. I'm just weary of spending on parts that don't help.

 

[Toms007]

Just a thought, did you replace the entire tensioner or just the pulley? Those tensioning devices can get weak. Just a thought.

 

[Vettepirate]

I replaced the pulley only. I thought it was the only moving part on the tensioner so what else in there could make that noise?

I also just installed a gatorback belt. Seems to have modified the squeaking noise but it's still quite audible. The old belt was damaged too so that eliminates the belt as the culprit for sure.

This problem has haunted me for a long time no surprise it's been that tough to locate the source. Will it do any harm to the car to completely remove the main belt and run the car to find out if it's actually something else entirely?

 

[Toms007]

I suppose that you could, for short periods of time. Seems like I've heard GMJunkie talk about replacing the entire tensioner, but I don't remember exactly what he was doing at that time.

 

[navy2kcoupe]

One thing to do without worrying about anything is to remove the A/C belt
just to make sure it's the main serpentine belt that's squeaking. If the
noise goes away, then it's in the A/C belt system and you can go from there.
I had a problem with my main belt getting thrown off, and replaced the belt. The
new one got thrown off too, so I started looking at other things, and finally
saw that the tensioner was shot. I replaced that and have had no more
problems. Good luck finding the problem.
Andy

 

[Toms007]

Thanks Andy, I knew that someone here had had the issue and was fixed by a new tensioner.

 

[Dad]

Got to go along with the idea that the entire tensioner should be replaced not just the pulley. While you have the belt off check all the driven pulleys to be sure they all rotate smoothly and freely. If it is damaging your main belt I would guess that it is not the AC belt that is the problem. Is the harmonic balancer wobbling? If so it can tear a belt out rather quickly although I'm not sure it would squeal while doing so.

Has anything been modified on this engine, like an under drive balancer? Are you getting the right sized belt so the stock tensioner can exert the proper tension?

Good luck

 

[Vettepirate]

There is a slight wobble on the balancer but nothing that looks like it's ready to self destruct. It's not causing any kind of damage to the belt that I can see. I am thinking this might be my problem. Strange part is that sometimes after driving for 10-15 minutes the car will stop squealing, other times it keeps going as long as the engine is on.

There are absolutely no mods that I know of on this car. I'm the second owner and it was sold through a GM dealer and it looks pretty stock in there.

I guess I'm gonna have to get into it a few hundred dollars more in any case.

 

[tmkassin]

Just fixed the same problem on my LT1. Turned out to be a bad harmonic balancer. When removed I could turn the center and the outer pulley in opposite directions with my bare hands. I chased this for months! It didn't look like it wobbled all that bad either.

 

[SG Lou]

DO NOT HESITATE to replace the balancer. Its a very common problem & if left alone will destroy your engine.

 

[LLC5]

There is a slight wobble on the balancer but nothing that looks like it's ready to self destruct. It's not causing any kind of damage to the belt that I can see. I am thinking this might be my problem. Strange part is that sometimes after driving for 10-15 minutes the car will stop squealing, other times it keeps going as long as the engine is on.

There are absolutely no mods that I know of on this car. I'm the second owner and it was sold through a GM dealer and it looks pretty stock in there.

I guess I'm gonna have to get into it a few hundred dollars more in any case.

Before you spend any money, try this first. With the engine at hot idle speed and the noise active, apply a small amount of lube (candle wax, silicone spray, etc) very carefully to the backside (not the ribbed side)of the belt running around the alternator and see if the noise goes away for a while. This will tell you if it is bearing related or not.

 

[navy2kcoupe]

Bad one on the left........Good one on the right.

Andy

 

[Dad]

Love that shot, can you tell if it has lost any tension? I see it's back against the stop but just a bit whopperjawed.

 

[navy2kcoupe]

Love that shot, can you tell if it has lost any tension? I see it's back against the stop but just a bit whopperjawed.

It still seemed to be as tight, tension wise, as the new one. It would allow the belt to ride forward on the underside
of the water pump, and eventually get too far forward and come off. I've checked about 10 other LS1's that I've been
able to see the motor on since I changed it, and so far this is the only one that has shown that kind of wear. I'm the 3rd
owner, so I don't know if it's the original or not, but it has less than 45,000 miles on it so I suspect that it's original. All I
can say is "if you have a tensioner that is starting to look like the one on the left, take my advise and replace it now
before it throws a belt." I was lucky in that the first time it threw the belt, I was in the garage. After I got the belt back on,
I put the necessary tools in the back in case it happened again. It happened a second time in the garage again, and I knew
there was something else wrong. I started looking at the belt travel with the engine running and noticed the belt sliding
towards the front of the water pump pulley, and knew that was not supposed to happen. The tensioner didn't look bad to
me until I put the two of them together, and VOILA the light bulb came on. Less than a 20 minute change time wise because
the main serpentine belt is the outside one, and it's the only one you have to mess with.
Andy

 

[Vettepirate]

My tensioner is drooping a bit but not nearly as bad as the one I see there. No thrown belts yet and I drove about 2000km last week to Chicago and back. I keep a breaker bar and a 15mm socket in the back just in case it happens.

Is a balancer hard to change on your own?

 

[Vettepirate]

I don't know if this would prove much but I tried to move around the tensioner a bit with a breaker bar with the car running. There was no change in sound from any of the positions I tried.

I assumed that it would stop squealing if I forced the tensioner momentarily into the 'correct' position (assuming this part is the problem) but no such luck.

Looks more and more like it might be the balancer... if my method is plausible.

 

[Vettepirate]

Found my problem!!!

It was the tensioner pulley on the AC BELT causing the raucus. I removed the AC belt and no noise. I turned the pulley manually and it must have kept going for a good 10-15 seconds on its own. The bearings must be totally gone. Now that I see this I hope my balancer has no part in this!

 

[navy2kcoupe]

Good for you! Replacement should quiet those crickets!
Andy Anderson

 

[Vettepirate]

Yes it will for sure.

Thanks for the help folks.