My C220 transmission has a very noticable high pitch sound coming from it at differnet ranges. It happens most between 2nd and 3rd gear. It started happening when the car and weather was cold. During the summer it goes away. Has anyone had this issue?

 

Mileage / History / Trans type...auto?

I assume auto.

First step check trans oil level.
NB you will have to make a dipstick (details on this forum) or alternatively take the vehicle to the dealer since MB "tamper proof" the trans dipstick access in order to avoid "non MB" trans oil being added.

Sure noise is coming from trans and not for instance PAS / AC / Alternator?

Stuart

 

My C200 year 2002 has been making that high pitch whining sound since day one.
It seems to be from the engine (M111) rather than the tranny and rpm dependent.
It comes on in any gear (auto) and at any speed around 2000 rpm and fades away as the rpm
goes beyond 2500.
According to the MB dealership here it is due to the engine design! True or false?
Shan.

 

MB will have more experience on this model than i do.

There answer is feasible (Cam belt design) BUT I would actually suggest that it is the Alternator that causes this problem especially since it is at 2000 RPM.
Try turning ON/OFF heavy electrical load whilst the noise is occurring. Does this significantly alter the pitch /amplitude of the noise as the Alternator has to work harder to balance load. Important to keep engine revs the same since the load will cause the engine speed to drop.

Stuart.