335xi clunk over speed bump

Has anyone else noted a "clunk" when going over a speed bump coming from the front end of the car? It only happens if I hit the bump with both tires together (not one tire at a time). It happens when going "down" the speed bump, not "up" it. To me it almost sounds like transaxle movement. If I go real slow, no clunk, only when I go fast enough to "fall" off the back of the speed bump.

I talked to BMW serive this morning and they had never heard of such a thing. I'm scheduling a service drive so they can hear it. I'll post when I find out, but I just wanted to get anyone else's thoughts....

matt

Hello, Matt. In this forum, search for "335xi bumps" and read the first thread. If your SA truly is not familiar with this flaw in the 335xi, s/he should read that thread too.

I can't stand the flaw. Though I haven't noticed it over speed bumps, it is very evident in my car, over deep or sharp edged potholes and over sharp ridges (which would be sort of like mini-speed bumps.)

If you can get this thing tuned out of your 335xi, please document the details of the fix and report it to us here.

Good Luck!

Snaxster

ever find a fix for this?

I would be curious about a fix as well.

I have a crunching type noise going over speed bumps. Seems to do it more when it is colder outside, although I have heard it when temps were as high as 40 degrees. I only hear it when I have the 17" winter tires mounted though.... Not sure if that is related or just because it is normally colder when the winter tires are on the car.

I just had this corrected under warranty a couple of months ago. After doing some research, I found that the noise (a crunching sound) that would occur going over speed bumps at slow speeds was due to the front stabilizer bar bushings. I greased them myself last year in an effort to fix the problem, using synthetic grease so as not to damage the rubber bushings, but the noise came back this year when the temperature dropped. I later read somewhere BMW specifies that the bushings are not to be lubricated (not sure about this, as other posters indicated that their BMW techs just lubed the bushings). So I disassembled the bushings and cleaned them up, took a test drive with the bushings crunching louder than ever. Made an appointment with my local dealer, and brought the car in a couple of weeks later. Of course, the weather was no longer in the 40's, and the bushings were quiet again. But here's what was done:

Although I could not hear it with my "naked" ear, the BMW tech was able to confirm that the front stabilizer bar bushings were making the noise by the use of a chassis ear (microphones mounted by the stabilizer bars to allow a second tech riding in the passenger seat to actually hear the noise and isolate it). He replaced both front rubber bushings and all is quiet now. I'm just hoping it'll last, as my research had found that this is a common complaint with our cars. Fixes have been anywhere from lubrication, bushing replacement, to complete stabilizer bar replacements, (with some posters indicating the noise returning months later).

I had the same issue when my vehicle had ~15K. Bushings of some sort were replaced under warranty and I have had zero issues with my suspension since. The car now has 62K miles.

Thanks for the info guys. My car goes in for it's first annual maint. and I'll have to bring this up. The noise is easily heard from inside the car.