For the past few months I’ve been experiencing a strange noise in my car at very low RPMs. It’s a tough sound to describe, but it essentially sounds like something rubbing. It’s certainly not a metallic sound, but almost like a rubber on metal sound. It happens primarily when I’m pulling away from a dead stop or shifting from first to second. I can also hear it if I leave the car in gear and decelerate from high in the RPM range.

Also, more recently the sound has become more prevalent and the clutch engagement has been inconsistent when the clutch gets warm. It feels like it engages at different points of release. When I turn the car off it also makes that rubbing sound, for maybe a ½ second or so. That makes me wonder if it’s something like a pulley that spins with the motor.

Drivability hasn’t really been affected too much, once I’m rolling the car drives and shifts pretty much normal and it still feels like I’m putting down all 450rwp. I can be sitting in 5th gear at 1k rpms and punch it and the clutch doesn’t slip at all, it just slowly accelerates away. My cousin is a master mechanic with Mercedes and he said that while he’s not terribly familiar with the S197, the only thing that he can think of that can make that sound is the throwout bearing.

I’m at a complete loss here and was hoping you all might have some ideas. The car is going into the shop on Thursday, but I’d like to have some thoughts or suggestions as I’d rather not go there without some other educated guesses.

Thanks for your help.

 

The noise you describe sounds like what I hear if for some reason the engine is about to die because I've stopped while in gear (when I first learned stick)

You said low RPM? Exactly HOW low are we talking? Under 1k?

 

Right around 1k rpms... just after idle.

Not sure what noise you're talking about though.

 

Assuming you're a 5 speed...

Take your car out to a long road and don't take the car out of gear when you stop - let it die. You'll hear what I mean.

 

I vote throw out bearing.

 

Assuming its the throwout bearing, would that neccesitate a fully clutch swap as well or can you just replace the throwout bearing and be done with it?

 

You can just replace the throwout bearing but since you're in there, it would be best to change the clutch and resurface the flywheel.

Why take it apart out once only to take it apart again later to replace the clutch (and possibly throwout bearing again)?