MB500

Guys,

Has anyone experienced any clunking noise coming from the trunk area when going over speed bumps or when the car body flexes? I don't get this noise consistently so it's hard to reproduce. But once in a while I hear a loud clunk coming from the trunk area when I go slowly over speed bumps. My trunk is free of anything. My car is also Bluetec so there is no spare tire. The only thing I can think of that could make such noise is the holder for jack stand. Has anyone else experienced any noises in that area?

BudC

I have a similar noise going over speed bumps. I've got an E550 with AirMatic and it has very poor rebound control compared to our W211 E350.

Raymond Lee

My car is 2012 BlueTec but no noise like it.

ttoE550

Are you sure the body is dead?

ImInPA

Sometimes when the AdBlue level gets low, the DEF can make a "clunking" sound as it sloshes around in the tank. I generally keep my DEF tank full.

MB500

That's a very good point. I am going to see if I can top it off.

MB500

Just checked and yes, it's nice and stiff

khelms98

I'm also getting an intermittent clunk that sounds like it's coming from the trunk area when I'm turning at about 5-10mph. I seem to hear it mainly when turning right at a decent rolling speed and applying the brakes. However, I don't think it has to do with the brakes. It sounds like a "boomp". Sound familiar?

MB500

Yes, it's very dull loud boom-type of noise. Very similar to what you are describing. I am having such a hard time replicating noise though and it makes it challenging to pinpoint the problem.

khelms98

I agree....I drove around making various right hand turns tonight trying to recreate it, to little avail. The times I heard it, I wasn't trying to hear it so I couldn't narrow down the exact details of the situation. Regardless, seeing as how I have an early-build '10 and you have an '11, I guess it's safe to say this is probably simply a characteristic of something that's inherent in all w212 models. I do have a sport model with pano roof (I mention that because some people have complained of flexing noises with the pano roof). Most people probably just don't notice, pay attention, or care when they hear a noise such as this that we're hearing.

My car could have been doing this the whole time I've owned it but I just happened to have the radio turned down, fan speed low, etc. at the right moment to hear it, and now I can't "unhear" it, if you will. I actually checked my trunk for loose items the first time or two.

MB500

To Khelms98:

Interesting, because I have exactly same P2 Sport configuration with the pano roof. It makes me wonder. But I wouldn't say that the noise is coming from the roof though -- it's definitely somewhere in the trunk in a hollow area.