This is comical. I dropped my car off this morning for this exact issue...it's a 2019! It's definitively valve related with sound emitting from the middle of the car and is not present when valves are closed. I made a video and sent it to my SA who wasn't able to discern the noise I described. I later got a call from the tech who had taken the car out for a drive and wasn't able to replicate the noise. I told him to take it out again, put it in S+ (valves open) and manual mode and to roll down the driver side window. Keep the car in 2nd or 3rd gears with hard revs to 5k and let the car decelerate to 2-3k and he'd hear it. I haven't heard back. Apparently he didn't roll the windows down (his words) on first drive. Seriously?

you can give me your video?

Scroll up and you should be able to see the video I uploaded and check if you have the same issue.

your video is not available

Here

YESSS ditto the same horrible iron noise is the H pipes valve

I just dont wanna write it out again but i shared how you can fix it

SA called. Tech wasn’t able to replicate the sound so I now have to go to the dealership tomorrow morning to take him for a ride. :wall:

Updating thread here. Took car in a few weeks ago to take tech for a ride. He heard butterfly valve rattle and applied high tem lubricant. Picked car up and immediately on drive home I could hear the rattle. This was a Friday.





Called SA following Monday to relay and said I wouldn’t be bringing the car back until there was a solution. That was 12 days ago. In the meantime, earlier this week. Having still not heard back, took my car to another MB dealership. Within 1 hr I was told they wouldn’t be doing any more lubricating as it didn’t work, and that a new exhaust was on order from Germany.




today I received a call from first SA telling me that I would need to bring my car back in for more lubricant and that they could have a loaner for me on the 18th. I laughed, and told him old already take the car to another dealership and that an exhaust was on order. I asked why they wanted to do more lube when it obviously didnt work the first time. He was speechless, never again

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The final fix after adjusting the metal clip was disconnecting the center valve and putting a AWE simulator. All rattles completely gone. I can still open and close the rear valves. Best solution to this problem out there. Just mad I didn’t do it sooner.

That is what I had to do because the dealership had the nerves to tell me that the issue was due to my secondary cat delete and that its also 'normal.' I gave up as soon as the master technician said that during a road test. I cut off the H pipe and replaced it with a straight pipe.Now I just need to change the exhaust and that should be the end of my mods.

Why cut it out? Was it rattling all the time? Just putting in the simulator and forcing the valve open stopped my rattle.

didnt think of that. just knew the valve was faulty and got rid of it.

How does that work? My understanding was the valve was always operational regardless whether you have the valve sims or the ASR unit (which I have, and still suffer the rattle)?

When valve is unplugged it stays in the open position. Simulator keeps the ecu from throwing a code. Rattle was coming from vibration in the valve as it was opening at 2500 rpm.

Interesting. I would expect the ASR to function the same... It was faulty though and I'm waiting for a new unit so hopefully when this one is fitted the rattle will cease.

The H pipe valve and the rear valves are controlled separately. The ASR module does nothing for the middle H pipe valve.

So just to clarify (before I drop some cheese on the AWE valve sims too) you have an AWE valve sim connected to the H-pipe and it keeps that 100% open?

Correct

Cheers, getting it fitted today so will report back!

Well, it's good and bad news really. After attaching the valve sim to the H-pipe the rattle has gone, the bad news is the car is noticeably quieter. With the ASR module attached the exhaust is really guttural and pops/bangs are super loud but with the H-pipe sim attached it's way, way quieter. No more guttural, gargling and pops/bangs are at least 50% quieter. I'm going to take the H-pipe sim off and suffer the rattle I think.

Hello All, I am new to the forum and recently purchased a 2016 C63s (Love it !!) which had the AWE complete exhaust system installed.
After driving for a bit, and since I live in a highrise apartment complex, I get to drive 8 stories in a parking garage to get to my parking spot,
it gives me a chance to put the windows down and listen to the car.

I noticed a "rattle" while the exhaust was "activated / ON "

That is what brought me to this forum as I was searching the internet to see what it could possibly be. (Thank you guys BTW - mbworld.org)

I took my car to a local mechanic and we put it on the lift to pinpoint the rattle, and we ended up finding it is the H Pipe valve.
(yes I am including a video as well)

I contacted AWE, (John and Shannon) were 1000% amazing and very helpful and supportive in directing me to the correct solution.
(yes it cost me some money for a new H Pipe - VERY FAIR!! ) but again, I was not the original owner or purchaser of the full exhaust.
(they also provided a link to help identify the issue : https://www.awe-tuning.com/faq/how-t...ctronic-valves

Waiting on the new H pipe now and definitely will update when I install it.

A few things about the "Rattle" and what I came across during my search on the web for a cause and solution.
(this is based on my situation)

1) the rattle was VERY noticeable when the exhaust was "ON"
2) while sitting in the car with the driver's side door open, you could def here it (middle of the car)
3) NOTE: if you were outside the car and near the rear exhaust, you could hear it as well, since it was resonating thru the exhaust backwards. - this caused me some confusion on the forums as I really didn't think about the sound traveling thru the pipes and making me think it was at the rear of the car
4) most post were referring to "down pipes" so I assumed I had aftermarket down pipes (but when I contacted AWE, they kindly informed me, they dont do down pipes) , so this threw me for another loop as I was uneducated in this area.

I will definitely update everyone and upload pics of my new beast as soon as possible.

Attached is the video so you can hear the rattle.
https://vimeo.com/nakedcbd/review/341823789/1846568d59

Interesting, that's different to the issue the rest of us are experiencing. Ours is under load when the H-pipe valve actuates at around 2.5k RPM. That sounds like the valve has completely detached! Congrats on the new ride :)

Long last! My own problem, AMG replaced the central part, at the moment it seems all OK I'll see if the problem reoccurs. However I noticed that the sound is less than before I don't know what they did.