Flash Gordon

This past weekend while I was driving on the hwy, all of a sudden I heard this unusual rumbling noise when cruising at 70 and above. When the car slow down the noise decreases as well. I exited out the hwy and pulled into a parking lot to check my tires visually......all looked good. Since I checked the tire pressure before started driving I knew it's not a pressure issue. Next, I opened the hood and listened for any engine mount problem......no noise from the engine compartment when the gas peddle was pushed. I was really at a loss. Got back on the hwy and drove for a while. The noise was gone. This was not due to the surface of the road either since the noise also surfaced on a strech of newly paved road! The noise came back intermittently since. I have not taken to the dealer yet since it is an intermittent issue.

Any one has experienced this before or heard of it?

DWP

A speed-related rumbling sound can indicate a bad wheel bearing, although I wouldn't expect it to be intermittent at a given speed. If you've got high mileage or have had any kind of a side impact I would have it checked out, though. While you're at it, check that all your wheel lug nuts are tight.

Double Eagle

I've had this with other cars and trucks with high mileage when differential bearings and rear end gears are going bad. Usually it's when I've used the vehicle to tow trailers. However, I've never had the problem with a MB. The problem usually starts at higher speeds on hot days and gets progressively worse. It's not intermittent but never gets better or goes away; however, you may not notice it on a cold day at lower speeds until rear end oil warms up. A dead give away for this problem is to feel the rear end and if it's really hot to to the touch, you probably have gears and bearings on the way out.

Flash Gordon

I only have 30K on my car. Can it be possible something to do with the Airmatic suspension?

konigstiger

Certainly, I know that rumbling noises for 2003 W211s without Airmatic was caused by excessive play in the bushing fastening the shock absorber and therefore solved by replacing the shock.

Even though you mention driving on a newly paved road you could mention this DTB in that it states the rumbling noise can be caused when the Airmatic compressor activates regardless of road conditions.

P-B-32.22/32 AUG05 Sporadic knocking/rumbling noise from front left of vehicle when the Airmatic compressor activates or when driving over rough roads – replace the compressor bracket. My copy claims up to VIN A735291 for the 211.070 (e500) however, this may have been updated.

Flash Gordon

Konigstiger, as always, thank you very much for your input I will ask my dealer to look into that.