hmm that sounds weird. Now im thinking if all of us with this rattling issue are even talking about the same thing


in my case, there is no rattle at idle. I only hear a hissing/rattle sound when under load between 2k 3k rpm and goes away if my exhaust isnt in S+.

Got the car back they can’t fix the rattle

Probably didn't make myself very clear but my car also does the 2k/3k rattle thing under load too. This is just a separate (well, maybe related) issue.

And they've just left it at that? Not good!

Yeah I don't have that sound... definitely abnormal... maybe that's the next stage of valve rattling... though I don't know anyone with that issue... this is probably a first as far as I'm aware

I bet if my car had that sound and took it to the dealer, they would try to convince me that it is normal LOL

Trip to the dealer for me then :hammer:

Same issue at 2500-3000 RPMs. That sounds like a different problem.

So I decided to upload a video to check if you guys are experiencing the same sound? Listen for that rattle between that 2-3k rom range.

I don't have rattle on revs... Just under load... Yours reminds me of the wastegate rattle from my N54

yeah.... no what the heck lol

how did you fix that?

Got my AWE valve simulators. Hopefully I get time today to get to the exhaust shop and get rid of this H valve. Fingers crossed for this one because if this doesnt work then I’ll have no idea what to do

I have the same issue, its when I accelerate when in a higher gear with lower RPMs than hitting a quick downshift to get the rpm up higher then accelerating.

https://cimg3.ibsrv.net/gimg/www.mbw...60843d6bc.jpeg
So happy to report that the rattling is a thing of the past now. Cut out the H-valve and replaced that pirtion with a regular straight pipe and connected a AWE valve simulator. Here is the bad boy causing me trouble

Strong work!! How is the exhaust sound now (aside from the rattle being gone)?

throatier in the lower revs and maybe a little less menacing at the top range but i need to drive more to see since i didnt really get a chance to go on the highway. Downshifts sound meaner though in S+ of course.

Drove a bit more and ill share my final thoughts.. startups are more aggressive as the car seems to pop more. I do hear pops and crackles randomly even in C mode. The H valve would change the tone of the exhaust as you accelerated but as one would expect without the valve, the sound is constant as you now have a fully open H pipe. At least my car doesnt sound broken with all that annoying rattling!. Hope this solves some of your rattling issues!

Nice to hear it worked man! Sounds like problem solved.

My rattle/clatter is fixed. Had it up in the air for a Service A and told my mechanic about the issue. Found a loose clamp on the wiring coming from the valve actuator. Problem solved.

Nothing that the worthless stealership would bother checking out or fixing.

feels like a new car without that stupid noise doesnt it!

And I agree, Mercedes dealerships are useless. Rarely do I have a good experience there. Every issue is normal according to them

I too have this problem... :( it was called an MB expert but nothing says it's a normal noise! I am forced to change the complete exhaust? Who found a solution?

i swear these mercedes dealers are the worst. Anyway my solution was to cut off the valve from the H pipe in the middle and replace that portion with a straight pipe. OR you can find someone selling their pipes and can just cut off the mid section and replace yours with it with the new valve. This is assuming your issue is the H-valve. Just check to see if the sound is coming from the middle of the car.

Thanks ... the sound it makes is horrible and I honestly don't understand how Mercedes does not make a call

no one was able to reproduce the noise? Mercedes wants audio proofs! Shameful!