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Oh man. If you've read the thread prior you'll see that welding it closed shut will screw the noise up and causes it to drone. It also will cause the car to have soft limp mode without an exhaust simulator. But simulators don't work on facelift cars.
All you need is one big clump of copper grease as it acts as a cushion to stop the spindle from rattling. The copper grease also doesn't "harden" unlike Mercedes's silver paste they use.
If you want to, increase tension and order a bigger springs from Mopar but from my tests a good amount of copper grease works on it's own you'll just need to apply it once per year.
If you're certain the grease alone doesn't work, get the Mopar springs, add some copper grease and you're 100% set.
Mopar part no. is 68319331AA
Now, unless the welds can be removed you'll need a new h pipe to restore that signature sound and remove the limp mode. Please don't weld or cut off anything else.
Guys please don't weld anything or close the h-pipe permanently. This is not the solution. I've done it all and it's not the way to go.
I've posted and tested fixes for this over the past 5 years and documented my results so many times on this and even on social media here:
Hi Jimmy I do appreciate your reply but I had tried the grease and personally I can't see how a spring would fix the issue if even welding it to stop it moving at all hasn't fixed the issue.
I removed the spring so it wouldn't try turning in a welded valve and break the actuator which I also reinstalled so the CEL won't show up as car thinks everything is the same. I also really like the sound now, it's louder through the whole rev range and I'm getting some nice tolerable downshift pops which I never got before as the FL has a quieter exhaust.
I'm just more curious why it's still happening at all and I can only think the other 2 exhaust tip valves are also rattling, have you found that issue?
Alternatively the H Pipe valve is still rattling away inside the pipe itself even after being welded so maybe I need to cut the whole thing out.
I just really want the rattle to stop, MB hasn't helped and this thread I've followed the instructions and it's still happening...
Listen to Jimmy mate. The spring/grease combo works. Get 3 springs, install them and you're done... but now you've f*cked the car by welding it and unplugging your valve without knowing it triggers limp mode.... whoops 🤷♀️
Can you feel the loss in power?
Last edited by George_1992; Feb 6, 2025 at 02:11 AM.
Listen to Jimmy mate. The spring/grease combo works. Get 3 springs, install them and you're done... but now you've f*cked the car by welding it and unplugging your valve without knowing it triggers limp mode.... whoops 🤷♀️
Can you feel the loss in power?
Haven't f*cked anything, welds can be removed. Made sure it was done that way to return to stock if I wanted. Cost $160 all up so not a huge deal to fix if necessary.
Also as I've written twice now, the stock actuator is STILL plugged in so not getting limp mode. There is no loss in power at all, just a better sounding exhaust IMO
Your comments don't help to assist and explain how I can stop the rattle even with the welded option.
Can I hear from people who've removed the H Pipe valve entirely? Has that stopped the rattle?
Haven't f*cked anything, welds can be removed. Made sure it was done that way to return to stock if I wanted. Cost $160 all up so not a huge deal to fix if necessary.
Also as I've written twice now, the stock actuator is STILL plugged in so not getting limp mode. There is no loss in power at all, just a better sounding exhaust IMO
Your comments don't help to assist and explain how I can stop the rattle even with the welded option.
Can I hear from people who've removed the H Pipe valve entirely? Has that stopped the rattle?
Then you're good to go... change the springs in the back two mufflers and add copper slip and you'll be rattle free
⏱️ 700HP Facelift converted C63 S Coupe with Drexler 3.06 plated LSD
Originally Posted by GLE53
Can I hear from people who've removed the H Pipe valve entirely? Has that stopped the rattle?
If you are happy with the welded h-pipe but still hearing rattles from the back two exhausts, change out the remaining two rear springs for Mopar ones add copper grease and it'll be fixed.
If you are happy with the welded h-pipe but still hearing rattles from the back two exhausts, change out the remaining two rear springs for Mopar ones add copper grease and it'll be fixed.
Ok so this kind of answers my question, thank you!
You'd agree that a welded H Pipe valve shouldn't be rattling anymore yeah? So if I'm still hearing it then it's the 2 exhaust tip valves causing this yeah? Did you find that with yours?
They are basically the same right so would have the same failure issue I guess. Will be trying the grease on those also tomorrow.
⏱️ 700HP Facelift converted C63 S Coupe with Drexler 3.06 plated LSD
Originally Posted by GLE53
Ok so this kind of answers my question, thank you!
You'd agree that a welded H Pipe valve shouldn't be rattling anymore yeah? So if I'm still hearing it then it's the 2 exhaust tip valves causing this yeah? Did you find that with yours?
They are basically the same right so would have the same failure issue I guess. Will be trying the grease on those also tomorrow.
If you've welded the h-pipe I assure you any additional rattles are from the back two mufflers.
I had one of my rear mufflers rattle as well but it wasn't as bad as the h-pipe and it make a cling cling cling sound. I used copper grease on the back two and never heard them again.
If you've welded the h-pipe I assure you any additional rattles are from the back two mufflers.
I had one of my rear mufflers rattle as well but it wasn't as bad as the h-pipe and it make a cling cling cling sound. I used copper grease on the back two and never heard them again.
Please let us know how you go man.
OK that's great will definitely be trying that tomorrow, due to where I could hear the noise I always thought it was just the H Pipe valve rattling but just went for a test drive and actually now the rattle isn't as loud and coming closer to the rear.
Upside of the closed welded H Pipe is that I really like how it sounds, if the grease on the rear valves doesn't work I may just weld them open also... Gonna be keeping this car so not a hassle for me.
Did you do the new Springs on the back or just the grease?
If you've welded the h-pipe I assure you any additional rattles are from the back two mufflers.
I had one of my rear mufflers rattle as well but it wasn't as bad as the h-pipe and it make a cling cling cling sound. I used copper grease on the back two and never heard them again.
Please let us know how you go man.
OK so the grease on the rear valves did help a little but I can still hear the rattle occasionally. I put it through the 4 holes on each valve but maybe it isn't getting to the exact place that causes the rattle.
Is it the spring that rattles or more the valve section?
Also what is causing the rattle now since those valves are stationary is it the vibration caused by the exhaust when driving because it doesn't happen while revving in park.
New springs, clean valve shaft with rust cleaner, turn it back and forth multiple times till it smooth, then put high temp grease on the top shaft def worked for me. Exhaust sound more pure now. Used to have all sort of rattles and clings and flip flap sounds.
OK so the grease on the rear valves did help a little but I can still hear the rattle occasionally. I put it through the 4 holes on each valve but maybe it isn't getting to the exact place that causes the rattle.
Is it the spring that rattles or more the valve section?
Also what is causing the rattle now since those valves are stationary is it the vibration caused by the exhaust when driving because it doesn't happen while revving in park.
Originally Posted by Joey911
New springs, clean valve shaft with rust cleaner, turn it back and forth multiple times till it smooth, then put high temp grease on the top shaft def worked for me. Exhaust sound more pure now. Used to have all sort of rattles and clings and flip flap sounds.
Are you going to keep it open with a valve module to prevent it from happening again or keeping it stock?
So my car is tuned and I noticed... even tho with new springs and valve lubed, with high boost level, there's a DISGUSTING RATTLE noise, that sounded almost like FARTING! Also sounds like wastegate rattle!
To clear my doubt, I did a WOT with exhaust valve close (Non powerful exhuast mode)... With the same tuned power level, the disgusting rattle fart noise is gone... so it is def not wastege making this noise. H pipe valve fart is only noticeable with exhuast in POWERFUL mode, and above stock boost level.
Imma try to increase pre-load on the spring next.
With high temp grease, scattered noise from the valves are gone tho. Smooth operation.
So my car is tuned and I noticed... even tho with new springs and valve lubed, with high boost level, there's a DISGUSTING RATTLE noise, that sounded almost like FARTING! Also sounds like wastegate rattle!
To clear my doubt, I did a WOT with exhaust valve close (Non powerful exhuast mode)... With the same tuned power level, the disgusting rattle fart noise is gone... so it is def not wastege making this noise. H pipe valve fart is only noticeable with exhuast in POWERFUL mode, and above stock boost level.
Imma try to increase pre-load on the spring next.
With high temp grease, scattered noise from the valves are gone tho. Smooth operation.
Man post a video of this bizarre sound i'll confirm if it's because of your map (tune) or exhaust flaps...
Man post a video of this bizarre sound i'll confirm if it's because of your map (tune) or exhaust flaps...
Wait are you telling me a shxtty tune cause fart? It's really hard to capture with all the wind noise but here goes... as soon as boot is built, FLAP FLAP FLAP FLAP FLAP FLAP FLAP. say it real quick. More apparent when WOTing next to a wall or in tunnel.
⏱️ 700HP Facelift converted C63 S Coupe with Drexler 3.06 plated LSD
Originally Posted by Joey911
Wait are you telling me a shxtty tune cause fart? It's really hard to capture with all the wind noise but here goes... as soon as boot is built, FLAP FLAP FLAP FLAP FLAP FLAP FLAP. say it real quick. More apparent when WOTing next to a wall or in tunnel.
A lot of tuners add their own sh*tty little burbles, backfires and exhaust flap adjustments into their tunes often without the consent of the customer. But to be sure you'll need to post a video.
A lot of tuners add their own sh*tty little burbles, backfires and exhaust flap adjustments into their tunes often without the consent of the customer. But to be sure you'll need to post a video.
So I was able to determine the tuen wasn't the issue. Pre -loading the center flap spring (seen on other thread) by twisting it more open (way harder to install back), the FLAP FLAP FLAP noise that I thought was exhasut leak/wastegate problem no longer present... and I did it to the muffler flaps earlier today. Let's see if all the rattles are gone.
@Jimmy_c63s Just wanna say you're an absolute legend for helping out in this thread (and overall forum I'd assume) for years lol. I picked up a 2016 C63s and am experiencing the exact same rattle in the H-pipe that @untamedd shared in his video (from Toronto too). Seems like the initial remedy was to weld the valve close to stop the rattle, which also makes the exhaust louder contradictory to what one would think. But putting copper grease in these 4 holes on top of the valve is also a viable fix? I'll tell my mechaninc to give this a try and hopefully it stops the rattlling. If so this would be the best case scenario, not excessively changing the exhaust nor breaking the bank lol.
⏱️ 700HP Facelift converted C63 S Coupe with Drexler 3.06 plated LSD
Originally Posted by Zlaatzs
@Jimmy_c63s Just wanna say you're an absolute legend for helping out in this thread (and overall forum I'd assume) for years lol. I picked up a 2016 C63s and am experiencing the exact same rattle in the H-pipe that @untamedd shared in his video (from Toronto too). Seems like the initial remedy was to weld the valve close to stop the rattle, which also makes the exhaust louder contradictory to what one would think. But putting copper grease in these 4 holes on top of the valve is also a viable fix? I'll tell my mechaninc to give this a try and hopefully it stops the rattlling. If so this would be the best case scenario, not excessively changing the exhaust nor breaking the bank lol.
Appreciate the kind words man. You've got to put quite a bit of copper grease on it. If you want to go the extra mile you can also order the Mopar spring but honestly the grease works on it's own.
I took a photo of how much it needs in my social media post here just have a scroll through
Appreciate the kind words man. You've got to put quite a bit of copper grease on it. If you want to go the extra mile you can also order the Mopar spring but honestly the grease works on it's own.
I took a photo of how much it needs in my social media post here just have a scroll through
⏱️ 700HP Facelift converted C63 S Coupe with Drexler 3.06 plated LSD
Originally Posted by W205C43PFL
Wow that is a lot more than the a lot I thought.
Gotta really pack it in there. Mercedes use half a tube of their rubbish anti seize on each actuator flap when you take it in and that lasts for 1 day tops.
Gotta really pack it in there. Mercedes use half a tube of their rubbish anti seize on each actuator flap when you take it in and that lasts for 1 day tops.
Good job on the repair and much appreciated for sharing with the community!
Are you going to keep it open with a valve module to prevent it from happening again or keeping it stock?
The H Pipe valve is welded open so it's coming from the rear valves now. Rattle has fully returned annoyingly enough, not sure if just because high road temps cos 35 degree summer days for last 2 months and daily driving. Will try the grease again before looking at welding the rear flaps open.
So I was able to determine the tuen wasn't the issue. Pre -loading the center flap spring (seen on other thread) by twisting it more open (way harder to install back), the FLAP FLAP FLAP noise that I thought was exhasut leak/wastegate problem no longer present... and I did it to the muffler flaps earlier today. Let's see if all the rattles are gone.
How'd you go after doing this to the rear muffler flaps?
The H Pipe valve is welded open so it's coming from the rear valves now. Rattle has fully returned annoyingly enough, not sure if just because high road temps cos 35 degree summer days for last 2 months and daily driving. Will try the grease again before looking at welding the rear flaps open.
I guarantee you it will work. The copper grease becomes a cushion and stops the flap from "clanging" on the cradle. That's what causes the rattle in the first place.
Mercedes lubricate it but their lube always turns hard after a few 100 miles and the rattle comes back. The copper grease won't go hard.
Please let us know how it goes. You only need to use 3x 5ml syringes worth and that rattle will be solved.
I use this syringe and poke it through the cradle holes to pump the grease in
hey @Jimmy_c63s tomorrow im going to grease my muffles flaps on my c43, so to choose 3 holes from total 4 on each side and through the cradle holes to put on each hole 5ml with syringes? (initially i thought high temp copper spray it will work good as the one you suggest) but now im thinking if i should fine somewhere in my city something like yours you used
p.s. should we clean with brake cleaner or something else or just applying the grease?
Last edited by KristiyanPetrov; Apr 24, 2025 at 03:15 PM.
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