Itīs passed services (just before i got it), and itīs not a sever technical problem. Just a very annoying sound.
It getīs quiet if i put in in 4īth gear.

 

if it it's rattling vibration that you hear. A common problem on the slk is a hard little grommet that brings the shifter and transmission linkages together. It breaks out and yes it's annoying. A cheap part, but a b---h to get at. not much room because of a heat shield. the clip is the problem, getting it off is bad enough. it's a one handed operation. putting it back on was easy if you put a small nail in the clip to keep it open until in place and pull the nail and presto. otherwise you can take loose the exhaust to get the heat shield out of the way. then you can use two hands.

 

Excellent. itīs exactly that kind of rattling vibration noise. Thank you.