cityhunter

I have about 1100km on my 2003 C32, and now I keep hearing the supercharger engaging (whine) even when the car is idling or cruising at a very low speed (about 10km/h). The whine doesn't go away even if I hold onto the brake for a while. But if I step on it and then let off the gas immediately, the whine will eventually stop (sometimes).

Is this normal? I thought the supercharger only engages at a certain rpm/speed. Is it because the driver adaptive thing now recognizes my driving pattern, and the supercharger is always ready for "action"?

Rowdy Audi

Superchargers are belt driven off of the crank and are always "engaged" as long as the motor is running. Superchargers also have some degree of whine to them. It's inherent to their design. There are a few reasons why it is starting to whine more now than ever is probably do to normal ware and tare. If it's a really loud whine, or more like gringing sound the oil port may be plugged and should be fixed ASAP.

av2

When the car was new, the whine was barely noticeable on the car. Now with 13000 miles, I don't remember hearing it anymore. Have your car checked out at the dealer. Why guess?

Rowdy Audi

That's a very good idea. Superchargers aren't cheap at all to begin with, let alone one that is on the 2003 C32. Making a quick trip to the dealer is far better than the supercharger locking up and leaving you stranded on the side of the road, just to figure out that Mercedes isn't going to cover it under warranty because of some technicality. And if it's just normal isn't it worth the piece of mind to know.

cityhunter

I am trying to avoid bringing it into the dealership, as its quite a hassle for me. If its something minor, I would rather wait till the next scheduled service. Thanks for the info anywayz.

Zeppelin

Well if you want to play with it some you can un-plug the supercharger clutch and drive it around. If the car still seems fast above 3000rpm then the electro/mechanical clutch is stuck on. But other than that not sure what it would tell you.

c32brabus

my '02 had the same problem with the noise and the dealer repalaced the whole supercharger to the '03 model. But now the noise is worst than it used to be. So now it's sitting at the dealer again. I'll have to see if they are going to fix it this time.

jswedberg

Not strictly true, on the C32 it has a clutch, so it is diengated at low speed.

As far as I can tell, the concern is whether the clutch is working correctly.

I do hear mine a lot, but I've been told everything is OK, so I've just gotten used to it!