Humming

[Carlos19664]

Hi All, I could really do with some help trying to solve this problem. I have a Mercedes ML 320 CDi Sport 2009. Since having the car only a few months I have noticed driving around town I can hear a humming noise coming from somewhere on the car from inside it sounds like a humming or vibration not all the time but more clearly noticeable on a motorway drive, at a constant speed if I then put my foot down its like a rubbing/humming sound, when I then take my foot off the accelerator it disappears only to reappear when I put my foot down again. Anybody had the same problem? I have a feeling it could be a driveshaft bush or engine mount but wouldn't that be more prominent all the time?

 

[Stratman]

Possibly the parking brake cable rubbing against the propshaft. The clips holding it in place break allowing it to float.

 

[Carlos19664]

Thanks Stratman, the only thing I would assume would make me think it could not be that is the fact that its quite a deep heavy humming sound, kind of like when two surfaces are dry and rubbing together I would think a breakaway cable wouldn't sound that heavy. Im due to have a mechanic take a look at it over a pit tomorrow so hopefully I should know a bit more