@Jimmy_c63s
Hi Jimmy,

Cut out H pipe, closed flap/disc in middle in closed position, welded H pipe back on, plugged in accuator , I did not touch any springs etc.

power seems to be fine, I’ve been in limp mode a week ago and I am currently not experiencing that.

there is one issue, there is a noise coming from both of the valves at the rear, a ticking noise.

I can only guess this is due to the AWE simulator not being plugged in , so the car is being told there is something not right (h pipe) so it’s causing issues with the back 2 valves?

I’m hoping once I get the AWE simulators and plug it in , the valves at the rear sort themselves out

It shouldn't be ticking at all. Simple test, jack up the car, unplug the H-pipe actuator (black plastic motor), see if the ticking goes away from rear?

The reason why I want to know if the H-pipe actuator was installed with the spring is because if you installed it with the spring and plugged it back in with the valve now welded to closed position, the actuator will be trying to open and close the welded valve whilst you're driving. And that will screw the actuator. Not that you'll need the actuator when you get your simulator, but you might want to make sure that spring is not in there.

Here are two photos of mine with the spring.
https://cimg3.ibsrv.net/gimg/www.mbw...d6871310e4.jpg

https://cimg4.ibsrv.net/gimg/www.mbw...bc2a962801.jpg

As you can see in the first photo, the top part of the spring on the actuator is designed to sit on the H-pipe valve to rotate it into Open and Closed position.

As mentioned, if your spring is still seated onto the valve and you've plugged it in, the car will still be trying to control that spring to open and close your (now welded) valve. Which isn't good.

@Jimmy_c63s
i will unplug the middle accuator and see if that makes a difference to the ticking from the rear of the exhaust.

I didn’t know I had to remove the spring so
its actively not working to try and rotate the flap.

shall I take the whole spring out or just adjust it so there’s it doesn’t attempt to move the valve in the middle?

If you plan on keeping the actuator plugged in until your simulator arrives you need to take the spring out completely then put the actuator back without the spring.

The spring pops off easily.

There's no point having the spring in there attached to a plugged in actuator that's trying to adjust your valve as the valve is now welded. This will only cause the actuator to break or throw another code.

Let us know how you go again with the spring removed and the actuator reinstalled and plugged in.

@Jimmy_c63s

Thank you, I will give it a try and come back with an update.

My 2020 C63s just started doing this. Apparently this happens on cars where the owners have been beating the car hard enough for the ehxaust temps to shoot really high which gradually dries out the lubricant in the valve motors. So technically even the rear valves can develop this rattle (this is not an issue for me due to using the ASR module to have it open all the time).

Now getting to the solution to this, welding the valve shut closed in the H pipe and then using a simulator is a modification that the dealership can notice from outside, so that is a no go for me as far dealership has made it clear that if they notice any modification that can affect the performance of the car in any shape or form, they will have to report it, which can technically get the cars flagged. Apparently Mercedes is super serious about this since Covid started, or my dealership is just an PIA. Either way, I want my warranty unaffected.

So I am going with solution from @Hyperion728 , where you open the valve motor and just remove the spring itself, so that motor just spins freely, so you will not get any codes. And then just weld the valve in closed or shut position within the H Pipe. Should solve the issue.

But I heard someone mentioning the car will loose low end torque. Is that true?

If your car is still under warranty, then I'd just get the entire exhaust system replaced.

I had this done to mine 10 months into ownership. The dealer said it was a common issue across AMG's... and they had just replaced a titanium exhaust in a GT-R prior to my car.

Had no issues at all since. I use an ASR module to leave the pipes fully open now.

Mercedes is not warrantying the exhaust system anymore due to the valve issue. They are saying it is just how it is. Atleast that is the lead AMG tech in my nearest dealership is telling me.

So does buying a new exhaust actuator part number 1909064500 not fix the issue?

Did you need to cut the H Pipe to weld the valve in closed position?

Interesting... that's unfortunate news but not unexpected I guess. Cost for replacing mine was around $6-8K according my dealer. They said the GTR titanium exhaust was north of $12K or something... lol

Nevertheless, I'd give another dealer a try and see if they'll be more nice. It looks like you're located in Canada which has different warranty policies than the U.S. I think. The Canadian warranty isn't valid in the U.S. (found this out recently while shopping for E63's).

The problem is that changing the actual exhaust or the valve actuator is not a permanent fix in this case unless they fix the design itself. It will keep on happening given you drive the car super hard. The exhaust temps gets really high and dries out the lubricant in the actuator motor, that is where the sound comes from.

So far @Hyperion728 's fix is the best one. Take the spring out and weld the valve shut. So everything looks stock from outside. I just want to know how he did it before executing.

Changing the exhaust actuator did nothing, bending the spring and applying grease did the trick. At least for now.

Which direction do you need to bend this spring ?

An answer to this question would be amazing. Multiple people have done this but never mentioned which way to bend the spring.

There is no answer here that is straight forward, bend the spring in the direction that will cause more force on the flap. Once you are looking at it in your hand and you see the way it sits at the flap you will know which way to bend it.

Ok guys, so I think the solution by tensioning the spring works really well. Atleast it has been working great for me so far. So no rattles at the moment. If it acts up again, I will go to the welding route.

Now for clear instructions this time:

1) Open the 3 bolts of the valve controller and motor and take it off.

2) You can fix these two ways. One is tensioning the spring and the other way is to weld the valve shut permanently.

Tensioning Spring Method:

Method 1: Tensioning Spring

You will see this rotary dial (picture below) which turns the main butterfly valve. Turn the valve all the way clockwise until you hit the hardstop (valve open position). This position is default anyway when you take the valve controller off.

You will now take the spring off the controller and try to turn the top portion of the spindle anticlockwise. This will put more clockwise force on the rotary dial on the butterfly valve eliminating the rattle. The valve controller will be difficult to install once you do this, which is kind of the point. This fix keeps everything stock and gets rid of the rattle. Spray some high temp grease on the motor spindle (where it holds the spring for good measure).

Method 2: Weld Valve Shut

I will pursue this route if the rattle comes back. Take the spring out of the valve controller, so the motor can rotate freely. This way you will get no codes and no need to disconnect the valve controller. If you take the spring out, the motor spinning force will never reach the butterfly valve.
Then turn the butterfly valve rotary dial anticlockwise until you hit a hardstop. This will close the butterfly shut, basically shutting the H pipe off (imagine having no H hipe at all). Then spot weld the rotary dial at the blue mark I painted. You can choose any other location as well but I think the blue spot is the most ideal place. This from my knowledge of welding should be reversible if you ever want to go back to the original setup.

https://cimg0.ibsrv.net/gimg/www.mbw...19a7b897d3.jpg

https://cimg3.ibsrv.net/gimg/www.mbw...94f8f44c70.jpg


https://cimg3.ibsrv.net/gimg/www.mbw...f55bf0381f.jpg

Can confirm this 100% works. Been watching this thread after this reply and kudos to this guy for making this write up. Disappointing to see the lack of replies or acknowledgement in this topic though. Another reason I've stopped posting much.

Someday, someone will Google this and come across this and learn how to fix their rattle.

This thread is awesome and is the reason I love forums in general. I don't have this issue yet but when/if it comes up I will be doing this 100%

Any updates?
I'm looking at welding the valve in the H-pipe as well, for the purpose of increasing the sound volume. Seems like a less expensive way to do so, as compared to buying new downpipes and/or mufflers, installing them, etc., and trying to retain the original exhaust note at the same time.
If you are now good to go, and others have benefited from this modification as well, then we are talking about, basically, just the labor to remove H-pipe, weld the valve shut, plug in the AWE simulator, and you're good to go.
Can anyone confirm?

I removed the spring on the actuator, spot welded the valve in the closed position and it still makes that crazy a** annoying noise. Very frustrated with this valve/the detrimental effects to exhaust note when modifying to fix the valve.

open to further solutions at this point. To be clear, I did remove the spring on the actuator and then plugged it back in. Car is running at full tilt/no check engine lights and the exhaust sounds how it should sort of. Still occasionally sounds neutered, like it did before the flap was welded closed. The fact that the valve still sounds like it’s flapping around seems like even in the closed position, the valve is bent and traveling further than intended. In my case, despite being welded in the closed position there is still travel hence the irritating and horrible noise.

Than
 

you have no idea how much this photo helped me today 😍😍😍

Another option to fix the rattle
 

Another option for those who are interested in keeping the factory H pipe setup for optimum sound, you can now buy a high quality H pipe from these guys $450 which fits with your current factory actuator/motor.

Just cut the old one out, weld this one in and it'll fit your with your existing actuator motor.

https://cimg6.ibsrv.net/gimg/www.mbw...436d4bdbbd.jpg

Specs say it'll fit 3" piping.
Can anyone confirm the size of our factory H pipe? Is it 3"?

https://cimg3.ibsrv.net/gimg/www.mbw...5c9f5d0ea.jpeg

Exhaust rattle
 

My 2016 c63 (with the performance exhaust) recently started making this metallic rattling noise whenever I'm on the throttle or revving the engine (doesn't matter if the valves are opened or closed). It sounds as if it is coming from one of the valves in the muffler, but I have yet to go and check. If anyone know what causes this problem, or knows of a solution, please let me know!

The video linked below is not mine, but it is an identical sound
https://youtu.be/8Dmbox4jZVY

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Another new topic on this? We have a massive discussion about it over here mate https://mbworld.org/forums/c63-c63s-...63s-coupe.html

Mods please merge topics