Greetings! I have the same problem with two E-class cars: 1999 E430 and 1994 E320 Cabriolet. Both cars have slightly over 100K. Both are in immaculate condition. Both have been driven conservatively only by adults. I would greatly appreciate any assistance/insights y'all could share to help me solve this very annoying problem.

There is a slight knocking underneath the floorboards of both cars. It seems to be worse on the passenger side on both. It seems to be getting worse very gradually but it's not bad at all. Most people don't notice it until I call their attention to it. It happens more on choppy roads or going over railroad tracks at low speeds.

I have changed the front shocks though they really didn't seem to need it. No difference. I crawl around underneath them on a regular basis to service and look them over. I don't see anything unseemly. I've repacked and adjusted the wheel bearings. Brake pads are new. Nothing seems to make a difference. It's easily reproduced (i.e. - it is not intermittent). It doesn't seem to be temperature sensitive. I don't notice it on the highway even when the surface is rough.

I had this problem on my 1972 220D and it turned out to be front subframe mounts; however, as far as I can tell, these cars don't have front subframes.

Any thoughts on what's going on here and what's involved in fixing the problem? I could certainly live with it because it's really not bad; however, it just doesn't seem to be right and I fear it might be a harbinger of bigger or pending problems.

Thank you for your insights.

Jim in Atlanta

 

Really folks? 357 views in the past two weeks and nobody has a clue? Seriously? I just happen to have the only two E-classes with this problem?