Coalman

I noticed that I sometimes get a short screeching sound when I get off the gas suddenly after getting on it in first or second gear. It sounds like a belt slipping. Has anyone else noticed this? Is it normal or do I have a loose belt or some other problem?

Thanks.

dbarrym

I am also curious if the belt is toothed or is it a smooth surface?

My Cobra replica (Ford 306 smallblock with Vortech V2SQ blower) has a smooth belt and will somtimes slip (squeek) or chatter at full load if it is too loose...

Coalman

I believe the belt is smooth. Also, I only notice screech when I get off the gas not when I'm accelerating. If it were a loose belt, I guess I should notice it more when I'm WOT? Perhaps it's something else besides a loose belt? Is there some kind of SC by-pass I may be hearing when I let off gass suddenly?

Jakpro1

If it really bothers you, swap out the supercharger belt for a fresh one.

Should only be bout 35-50bucks and that takes it out of the equation.

I still think supercharger belts should be swapped out MINIMUM once to twice per year.

Unless you have one that is a month old or something, couldn't hurt.

jangy

I agree with Jim. You don't reuse rubbers, so don't push belts too far, either.


Given that, what you are describing is very normal. it happens if you take your foot off the gas while the car is in the powerband, NOT if it has spun out. that is simply the momentum of the SC causing a screech as the motor decelerates rapidly. You can get it to do it even more in manual mode. To be honest, i don't know how stressful that is on your engine internals. I think people often forget the amount of power we have and the damage it can cause if abused.

ChicagoX

Jim speaks the truth.

I went with a slightly-smaller belt (Jaguar) and the screeching stopped; it's a tension issue.

Coalman

Thanks for info.

Can it be only $35 - $50 if the dealer does the installation? I wouldn't know the first thing about doing it myself.

jangy

The install is extremely easy. When facing the motor, the belt tensioner is to the left of the SC clutch. I use a, 11/16th to pull the tensioner and that loosens the belt. You pull it off, put on the new one and go. That easy.

DJE55

It's a pretty normal thing for these cars. Mine used to do it all the time. Check out the vid below and listen. You'll hear the belt right after i let off the throtle coming out of the burn out.

www.fquick.com/videos/viewvideo.php?id=1221

Coalman

Yep, that's the sound all right. Is that the belt or the SC?

FLSL55

Here is another vid of the sound.
http://www.youtube.com/user/roadtest.../1/LqPu3WmUQKE

I think the supercharger clutch takes a second to disengage when you lift.

E55AMGGG04

I've heard that sound 1 too many times .

daniel3ooo

does this screeching sound occur when you cold start the car?

ahmad0658

I have the same sound on my car, when ever going from 1st to 2nd gear, or sometimes when I accelerate. Also, I would hear it if i hit the gas small kick at zero speed.

The only thing I noticed is that when I took it for steam wash, I did not hear this sound for almost 3 days and it came back again later .

If anyone having a solution for that, it would be fantastic.

06E55

Coalman, there is an excellent DIY article for changing the supercharge belt in this (w211 AMG) forum. It is very easy to do and will take you a whole 5 minutes.

Yuille36

I think that you would be better off changing the belt. Your engine may be spinning at 7000 rpm, but your supercharger may be spinning at 14000 rpm, then you get off the throttle, that SC hasn't slowed down at all causing the belt to slip, because the belt can't hold back all that rotational mass. If it's slipping and crying about it, then it can break leaving you stranded someone. Change it out, better safe then sorry, I always say.

ahmad0658

I have seen a lot of comments around not only in this topic, saying that change the belt and you it would solve the issue.

Just to eliminate that option, I have recently changed my belt which finally arrived from Brabus (recommended to change the belt of Brabus every 10 000 km, changing is nothing to do with the sound) after 2 weeks waiting and the sound is still there. Only when I took my car for steam wash, the sound disappeared for 3 days and then the sound has came back !!!

FLSL55

Eco,

I think we are talking about two different things here.

The sound I think you are experiencing is the supercharger clutch. When it engages it can cause a screech sound. You need the updated clutch....

ahmad0658

hmmmm,

What kind of S/C's update I should make ?? Is there any DIY or thread about that ?

FLSL55

Warranty, if you still have it. Or pay out of pocket and install the "06' Clutch pckg" at dealership.

That was a known issue on '03-'06 models caused by a slipping supercharger clutch. The chirp I am talking about occurs only during acceleration around 2000 rpm when the S/C engages, doesn't matter if engine is cold or hot!
away when the engine warms up.

ahmad0658

unfortunately, I am having this sound if i step on the accelerator and when it shift sometimes from 1st gear to the 2nd.

Also I have it when I accelerate hard .

I told the dealer, EMC (Emirates motor company who has the biggest MB workshop in the world) and they said it is normal and never mentioned anything about 06 clutch package and difference

Dealer = Stealer

FLSL55

Hmmmmm, I think your problem could be one of two things. The first is easy and cheap to fix.

1 your supercharger belt needs replacing.
2 your clutch pack needs rebuilding or updating to the new 06+ configuration.

I would start with installing a new supercharger belt first. I think that may be your problem.

tarekc

hi guys my sc belt keeps coming off i got a new one same problem after a few hard pulls! i think the tensioner spring or whatever it is, is past its time? any ideas
thanks