I have an '05 MCS with 67k miles, and i have a weird belt/pulley squeak/squeal. When I drive, it goes squeaksqueaksqueak... squeaksqueaksqueak... squeaksqueaksqueak... from the belt area. It gets faster and louder with the engine revs, and it looks like there are wear marks on the flat part of my belt, maybe 2-3mm from the edge closest to the engine. It started after we installed a brand new belt, idler pulley, and a tensioner with 45k miles on it. We figured the tensioner with less miles would be better than my original, and the bearing/strut on it felt ok.

The car is stock, excluding a header and exhaust.

Any ideas? I think all things point to a bad tensioner

I tried searching, but it's something I haven't been able to find... I know it can't be a unique problem. Any advice would be greatly appreciated!

-Joel

 

get a length of 1/4" hose and use it as a stethescope to find just where it's coming from. Then you'll know exactly what part has a problem. Then you can go to work on it.

In a way, a repeatable noise is a lot easier to find than other things that are rare and intermittant.

Matt

 

Good idea to use the hose... It's hard to put a probe on a moving pulley.

:thumbup:

 

A prybar or similar is a little easier to use around the belt train, since you have to be careful not to touch moving parts. It may be your belt squeaking, but it may be due to a bad bearing in the tensioner or idler pulley. by *carefully* putting the prybar on the tensioner bracket and idler bolt, you should be able to hear bearing noise if there is any. You can also release belt tension and spin the pulleys manually. If a bearing is quite bad, you'll feel the crunch.

 

you're paranoid! My three fingered Auto Shop teacher said you don't need to worry about moving parts!

Matt

 

Well, the squeal went away... but! There's still a clear wear mark on the belt.

My new tensioner and belt come in today, so I'm just going to take the whole front of the car apart, and find out what is/was rubbing on my belt. :D

I'm sure I'll find at least one gasket or seal to put on order as well...

 

Alright, I just installed a brand new tensioner and belt. The squeal came back this morning, but there are no apparent wear marks on the belt yet. I used a hose and a long screwdriver, and I cannot tell where the squeal is coming from, apart from the belt area. Should I just wait to see if it goes away? Or should I go all out and replace the supercharger next? I'm kinda at my wit's end, and so is my mechanic. Has anyone ever heard of this before? Could I have installed something wrong?

 

alright, I just uploaded a video I took of the noise. I know it sounds like a pulley but it's not, it goes away with belt dressing applied.

http://www.youtube.com/watch?v=0swnO...=youtube_gdata

 

Sounds like the squeek and the belt were two different issues.

How long was the first belt on there for ? It could have just been stretched out some from useage causing the belt to drift some under load.

How did the rubber hose trick go. Any chance it is coming from the Alternator or A/C compressor ? Did you spin the pulley for each of those components with the belt off to check for the noise ?

BTW: your video link is no good.

 

Ok it's like this. I bought the car, it had a bad pulley bearing. Made a bad bearing whistle sound. All the pulleys felt fine besides the idler and tensioner. Installed a tensioner with 40k miles on it because it was free, no change. Installed a new idler pulley. It fixed the bearing noise, but a few days later (about 200mi)... Squeaksqueaksqueak. Replaced the belt, and started getting a loud consistant squeal. Took it to the mechanic, they said the a/c compressor was misaligned, some bracket was broken... They fixed it. Again, maybe 1-2 days later, squeaksqueaksqueak. There was a groove along the flat side of the whole belt, and I figured it was from whatever was wrong with the a/c. I bought and installed a new tensioner and belt, and it went away for 2 days. And... Squeaksqueaksqueak, but there is no groove in the belt. I didn't have it before the first tensioner/idler swap, and since the tensioner wasn't new, I figured it was the culprit. Now I'm starting to think it may be that I improperly installed the idler, or I may have bought a bad one.

The video link is fixed.

Ps... The alternator and ac compressor feel like ever other I have felt in my life.

The whole time, I haven't been able to pinpoint exactly where it's coming from.

 

Are you running a belt tensioner stop? This may sound stupid but I have ran across this problem. If the stop in installed incorrectly it could be making that noise. The bolt that you put the stop on closer to the window, if it isn't lined up with the bolt, and instead farther in, it can actually cause the belt to lift up and make a very similar noise and cause a belt wear in one side.
Just throwing the idea out there..

 

Sorry man, no stop on there yet, and when I installed the tensioner I tightened all the bolts down evenly and in steps to make sure it was straight.

 

If you find the source of the problem or any things happens, keep us posted, I'm curious to what the problem is..

 

As suggested above, careful use of a rubber hose should pinpoint the location.

You may have to put the car up on stands or a lift, remove pass side wheel and wheel well liner so you have better acess to the pulleys and listen again.

Take a close look at the compressor / work done.

 

The alternator! It came slightly out of alignment and was just a bit loose, and when the car would warm up and the belt would stretch, it would cause the squeal.

And my thermostat housing has a leak. The journey continues...

Thanks for all the help!

:thumbup:

 

lol, my car just started making the same noise, goes away when its warmed up, time to check all the pulleys, yay!

 

alright, it's definitely coming from the tensioner pulley.... really glad its not the SC pulley, it was close enough to where I was concerned...

who wants a wager? should I wait and see if it's a real problem(hooray for chucking belts), or replace it right away like a good boy? also, anybody know if you can lubricate this pulley???

oh, and my noise is a higher pitched chirping, not a the same as the youtube video posted earlier.