rubensans

Hello,

Since some time like 5 months or so, when I start the car at cold after 12 hours beeing stoped, I hear a very huge vibration on the front of the car that remains aprox 1-2 minutes. You never have the vibration if the engine is in neutral. It only apears when you have "D" or "R" selected and the brake aplied or going at very low speeds. You have a little more if you are turning.

I toke the car to the dealer and they said and I saw, that the belt tensioner of the supercharger belt was bad; you can see how it vibrates up and down; in the direction wich it tenses.

With the new tensioner the sound disapeared 3 days and then it has progresively reapeared. We will change the tensioner another time.

Any idea of what could be? The mechanic said it could be the new tensioner bad or that the kompressor has more friction that it should have, could it be in the eaton kompressor maybe the spacer between the nose unit and the actual rotors.

Please give me ideas !!!

Best Regards and Thanks.

Ruben.

P.S. 2002 Sportcoupe C230 Kompressor.

rubensans

We have been investigating and we have some data after replacing 3 tensioner pulleys’s but not the solution.

I have installed some time ago a Brabus pulley with a Contitech rubber belt.

We have see that with new belt tensioner, when you start the car in cold, the first 60 seg the tensioner makes some movements (pulls) to the maximum limit and then it stops, after doing that 10 cold starts the rubber mounts of the tensioner limit wear out and you hear that rattling noise.

Then we think that the problem is that the belt is to long, and we should see if on another M111 when you start in cold the tensioner has some normal movement inside the limits if it have then it’s only the belt that is too long and allow the tensioner go to the limit.

Can anyone can make a test (2 people need and a M111 sportcoupe):

With the engine cold after 12 hours:
Mr. A: Enter the car and release the hood.
Mr. B: Open the hood and with a flashlight illuminate the tensioner pulley of the kompressor belt.
Mr. A: Start the engine.
Mr. B: See if the tensioner pulley is stable.
Mr. A: Press the brake pedal and put reverse, move a little bit the steering to one side.
Mr. B: Check if the tensioner pulley is stable or has some kind of movement.
Mr. A: Put Park and stop the engine.

Best Regards.

rubensans

A video of the pulley shaking and the sound:

http://www.rubensans.com/temp/MOV06987.MPG (50MB)

WyattEarp

I have a Kleeman pulley on my coupe and I've actually had the superchager replaced by the dealer due to this noise. I am definitely interested in the results of you test.

This also leads me to my newfound lack of respect for aftermarket modifications. No matter what anyone says they affect the car adversely in the long run.

if I want more power I'll just spend more money to buy it from the manufacturer.

rubensans

Replacing the supercharger has solved you the problem? How much is a new supercharger?

Best Regards.

Ruben.

WyattEarp

The Supercharger was replaced under warranty so I don't remember the cost. I'll look at the service record and see if I can find it when my wife gets home.

Replacing the superchager only fixed the noise temporarily. It came back eventually.

rubensans

Please take a look on the service record to see if they have also changed the supercharger pulley tensor or it's rubber mounts.

There aren't lot of people with this problem, but at least 4 or 5.

More info: http://www.mbklasse.com/forums/showthread.php?t=11756

Our M111 engine has the tensor directly fitted to the engine, other M111 engines have the tensor fited with a shock absorber. This is why it may be so sensible to the belt lenght.

We will keep investigating.

Best Regards,

Ruben.

P.S. If someone have a original M111 crankshaft pulley and don't want it, I will do some tests with it.

mleskovar

This should be a public service announcement. Unless you are going to seriously race and accept the subsequent reliability problems why disturb something that has gone through many hours of engineering and testing for a few more hp?

rubensans

On the other hand I don't think Brabus, Kleemann, Carlsson, Väth, MBK, etc... makes something that compromise the reiability of the engine.

Best Regards.

mleskovar

Even after what you're going through now? So you don't think that's because of the mod you made? They have neither the resources nor the combined engineering brainpower of the manufacturers. I'm not saying their products don't work but they compromise the integrity of the engineering for minimal gain.

rubensans

In fact I'm not sure, but I think it's a problem with the lenght of the belt. So I think it's because of the mod.

On the other way, I haven't modified any of the following items and had problems with them: sunroof + torsion bars + shocks + command + rear cover + EZS so mercedes engineering brainpower also has lacks !!!

Best Regards.

mleskovar

Good point

rubensans

Hello,

Now the car is stock and still have the noise.

We have try a lot of belt sizes, change tensioner 4 times, rebuild supercharger, etc.. And we still have the noise in the tensioner pulley.

Right now we have take out Brabus K3 kit and return to stock and the car is going to be inspected by Mercedes.

Will keep you updated.

Best Regards.

C230 Sport Coup

I'm back to stock, and it isn't as noticeable.
I'll put my ear a little closer and take a look under the hood to see what really up. Put it in D and put on the parking brake.
Meanwhile, I'd greatly appreciate the tentioner PN's, and
any other bits I should think about replacing before going back to ASP. Assuming its not too expensive, or hard to replace I'd like to do that when I swap the pulley back to ASP.

C230 Sport Coup

Did they replace the SC even with the Kleeman pulley in the car?
If so, they didn't balk about it at all?

rubensans

It's seems that in my car the problems where a mix of the supercharger coupler and the belt tensioner (this last was the real problem)

The worst is that all tensioners that we have put where from a old series (they had them in stock). We have ordered a new tensioner in MB-Spain that comes from germany and right now they are instaling it.

So it's like we have been fighting with a series of defective tensioners.

Belt Tensioner A1112001370 (85€).

Best Regards.

Painful

I have a completely stock M271 doing this same thing. Gonna replace my tensioner this week and see what happens.