fapfap1108

Hi guys,

This is my first post on this forum. I have a 2013 C300 Sport 4matic. I've been having this issue for a while but I'm not sure if it really is a problem.

When I'm at cruising speed around 70mph (~2000rpm) when I hit the gas pedal, there is a noticeable buzzing noise, which I'm not sure it is from the engine or the exhaust. When I let the gas pedal go the noise disappears. If I manually switch the gear to 5th (~3000rpm) the buzzing also goes away.

I'm planning to go to the dealership next week to check it out. Any suggestions or it is normal?

BTW I had my ECU tuned by Kleeman

Thanks in advance!

Atlas Grey

Exhaust rattle maybe? IS it any any acceleration or just cruising speed?

fapfap1108

It happens only at cruising speed. Normal acceleration wise it is normal.

TaycroTC

Tranny or motor mounts maybe?