I’ve got a challenge for you awesome MB people!
The sound is similar to the sound you made when you as a child attached a piece of cardboard to the spoke of the wheel of your bike to make it sound like a motorcycle (best possible illustration J).
The noise is very loud and sounds as if something metal repeatedly hits another metal piece. When you turn off the engine and leave the car for a while, it drives again as if nothing has happened. It sounds like the noise comes from the underbody of the car just behind the front seats. HOWEVER, the driving properties are not affected at all! What makes this even weirder is that the lightest touch on the gas pedal makes the noise disappear until you lift your foot from the gas pedal or apply the brakes.
I join my repairmen in not having any idea what might cause the loud noise. Since it’s far from cheap to have them run around my car, blindly trying out different hypothesis, I need the help from you professionals!
I love my MB and I want to be able to drive if for longer than 15 minutes at a time! J
Kind regards,
Christian
I had issues with a '98 S420 with the drive shaft but the noise associated with it and the vibration got worse with the speed of the engine as you would expect.
Good luck with that one.
Mark


