cristinel.casu

Hello all,

I own a W211, E280, M272, 3.0L Mercedes. Ever since I've bought it I'm facing a strange noise that is occurring both while the car is still (e.g., both in Park or Neutral) but also while driving it. To be more specific, there is rumble noise compensated with a cabin vibration that can be heard and felt while revving up the engine (i.e., the car is still, either in Park or Neutral). The highest intensity where I can feel it is around 2000-2500 RPM and when the engine is cold. It is still happening while the engine is warm (e.g., 90 degree celsius) but with a slightly lower intensity. To note here is that the noise and vibration are not synced with engine rotations, but they increase and decrease their intensity at every other 2 seconds or so. I would also like to add that I cannot feel or hear anything while the engine is fully idle, even when it is cold. Could it be caused by engine mounts or is there something else I should look for?

Rumble noise example: https://youtu.be/926a-7b9EIs

Thanks!