Supercharger belt making squealing noises...again...

B6/7 S4/RS4
#1

This is now the third time my supercharger belt is making squealing noises at RPMs above 3k. The last time this happened, my mechanic sprayed a minute amount of oil on the belt just to see and the noise went away for a few minutes (it was a very small amount just to confirm).

Anyway, since I needed to get some routine maintenance work done on the car at the time, I had the belt replaced just to be safe (small amount of work with the front bumper already off).

It was fine for a short while (about two months) and then I got a car wash and it started happening again.

What could be causing this? Is it the water spraying directly on the belt during a car wash that could be causing this?

#2

Most likely improper alignment or improper tension. I’m not sure the car wash has anything to do with it, unless some kind of product caused some type of residue on the belt.

#3

Hmm…well, seeing as it was fine for 2 months and my mechanic did everything to the letter (and he’s done it multiple times) I’m having difficulty believing that’s what it is to be honest. Before this last belt replacement, the belt didn’t make a noise for over 6 months.

Improper tension/alignment from an improper install would have made itself be known sooner no? Add to the fact that it started happening about 1 minute after I left the car wash. Maybe the spray caused the belt to come out of alignment? Those are some heavy duty jets.

#4

I had a similiar issue with my serp belt, I’m not supercharged but it was same issue. It took a couple months for it to squeal, replaced the belt, it came back.

I found my tensioner was actually bent causing a misalignment. Only took 4 belts for me to realize what the issue was.

http://i60.tinypic.com/k1aznl.jpg

#5

Thanks for the input. Msybe that’s it. Will make sure a proper inspection of the tensioner will be performed.

#6

Axel I didn’t really mean it was installed improperly…but something may be wearing the belt incorrectly like aroderick just mentioned.

You have been supercharged for a while, I’d talk to JHM and ask them about their revised rollers/pulleys. One of the. Could have a bad bearing or something.

#7

This.

I got all the updated pulleys and the automatic tensioner for my car. Had an annoying battery light that kept coming on when pushing to high rpms. Just need warmer weather to install everything since it is too cold outside to work on anything other than oil changes and very basic maintenance.

#8

I already have all the new pulleys and “stuff” from JHM.

#9

After reading your first post again, I noticed you said it only squeals above 3k? My misalignment cause squealing at idle so I am not sure how relative my situation might be.

I would pull the bumper and look at the belt to see if you can see if its straight across all the pulleys and idlers.

#10

Interesting…Last time he checked it all looked good (this was before replacing the belt again). Haven’t taken it to him recently. Next time I go, I’ll ask him again and to specifically check the angle of the tensioner.

#11

so just to confirm u do have the new automatic tensioner?

I would use a straight edge across the crank pulley and then to all the other pulleys to see if anything is out a bit. I just did that to confirm mine were all straight on my own car.

#12

What kind of belt? Gates?

Cobra SC belts squeak too. The solution is to scuff of the non-ribbed side with 220 grit sand paper to get rid of the shine.

If not that then the other solution is to use a Gates Fleetrunner belt. They’re green. And for some reason they grip better and don’t make noise. About double the price of a regular belt though.

#13

Before you do anything check to make sure you have the new update auto tensioner. In theory if you have the new tensioner that should never happen. On acceleration the belt tightens up. If this happened just coming out of the car wash the wax or detergent could have gotten on the pulleys making it slick. Also could have washed some oil onto the pulley. Is this still happening days latter.

#14

You need a bigger supercharger . That must be it !

#15

A couple updates.

  1. I don’t seem to have the latest tensioner. Maybe something I should look into getting.

  2. I can confirm this is ONLY happening when the belt gets wet. When the belt is dry, it’s perfectly fine and quiet. But when it gets wet, it squeals like a pig the higher in the RPM range I go. At idle and low RPMs, it’s quiet event wet. But as I get to 3k rpms it starts squealing and gets louder as I approach redline.

The location of the belt is very low and fully visible from the fog grill. This means that water gets to the belt very easily if it’s wet outside or if I’m plowing through heavy snow.

Maybe I should look into filling in that grill? Or put a mesh to reduce water but still let air through?

#16

Not saying I told you so but … you know.

Supposedly there is a block off plate that is supposed to come in the SC kit to block off the opening by the fog light grill opening. JHM was supposed to ship it out to me but after asking twice and not receiving it I gave up.

#17

The new tensioner would totally eliminate all that. So maybe think about getting that. The block off or extra screen is a good idea to reduce the snow from getting in there and melting. During the summer I would say remove the block off of you fully block it off.

#18

How would it eliminate the squealing noise from getting wet? What physical changes exist in the new tensioner for a wet belt to no longer make noise?

#19

I’ve Actually Seen the tensioner in action. As your rpms go up and the tq on the belt goes up the tensioner adds tension. Right now your tensioner is set at one point and it’s fixed at that point. The auto tensioner will add tension as needed. It’s pretty slick.

#20

Ok, cool. Thanks. I sent JHM an email this morning. We’ll see if they reply lol