Exhaust Rattle C63S coupe.
MBWorld Fanatic!
Joined: Sep 2016
Posts: 1,718
Likes: 608
From: Australia
⏱️ 700HP Facelift converted C63 S Coupe with Drexler 3.06 plated LSD
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?
p.s. should we clean with brake cleaner or something else or just applying the grease?
No need to clean anything unless there's mud or crud inside.
The Mercedes techs don't clean, they just hoist the car up and stick the nozzle of their little paste tube into the holes and squeeze. I've watched them when my car was new and I use to bring it in for "warranty" to fix the rattle.
Went so many times I even pinched the paste tube out of their bin and that's how I found out what they use.
But that Mercedes paste is rubbish hence why so many people still get the rattle after a few days when they apply it.
Use any brand of copper grease (copper slip) as long as it's not spray.
MBWorld God!
Joined: Dec 2019
Posts: 32,222
Likes: 6,279
Are your flaps rattling?
No need to clean anything unless there's mud or crud inside.
The Mercedes techs don't clean, they just hoist the car up and stick the nozzle of their little paste tube into the holes and squeeze. I've watched them when my car was new and I use to bring it in for "warranty" to fix the rattle.
Went so many times I even pinched the paste tube out of their bin and that's how I found out what they use.
But that Mercedes paste is rubbish hence why so many people still get the rattle after a few days when they apply it.
Use any brand of copper grease (copper slip) as long as it's not spray.
No need to clean anything unless there's mud or crud inside.
The Mercedes techs don't clean, they just hoist the car up and stick the nozzle of their little paste tube into the holes and squeeze. I've watched them when my car was new and I use to bring it in for "warranty" to fix the rattle.
Went so many times I even pinched the paste tube out of their bin and that's how I found out what they use.
But that Mercedes paste is rubbish hence why so many people still get the rattle after a few days when they apply it.
Use any brand of copper grease (copper slip) as long as it's not spray.
Super Member
Joined: Nov 2022
Posts: 512
Likes: 86
From: Bulgaria
C43 AMG '17 / Stage II
Are your flaps rattling?
No need to clean anything unless there's mud or crud inside.
The Mercedes techs don't clean, they just hoist the car up and stick the nozzle of their little paste tube into the holes and squeeze. I've watched them when my car was new and I use to bring it in for "warranty" to fix the rattle.
Went so many times I even pinched the paste tube out of their bin and that's how I found out what they use.
But that Mercedes paste is rubbish hence why so many people still get the rattle after a few days when they apply it.
Use any brand of copper grease (copper slip) as long as it's not spray.
No need to clean anything unless there's mud or crud inside.
The Mercedes techs don't clean, they just hoist the car up and stick the nozzle of their little paste tube into the holes and squeeze. I've watched them when my car was new and I use to bring it in for "warranty" to fix the rattle.
Went so many times I even pinched the paste tube out of their bin and that's how I found out what they use.
But that Mercedes paste is rubbish hence why so many people still get the rattle after a few days when they apply it.
Use any brand of copper grease (copper slip) as long as it's not spray.
just placed left/right side on each hole (3of them) 5gr/ml high temp copper grease and will report after few starts how it feels, thank you for the feedback
not sure when i bring in stealer for service if they do that at all because i never saw in the invoice grease charge or anything else or maybe is included in the service who knows haha
Member
Joined: Jun 2014
Posts: 169
Likes: 22
2014 CLS550
Anyone else got it?
With the exhaust in "open" mode there is a distinct metallic rattle coming from the drivers side under a load that's driving me crazy. Sounds very much like the baffle or flapper in the exhaust is rattling around.
Anyone else having this issue? What did you do about it?
Haven't been to the dealer about it yet but will take it up on the first service.
With the exhaust in "open" mode there is a distinct metallic rattle coming from the drivers side under a load that's driving me crazy. Sounds very much like the baffle or flapper in the exhaust is rattling around.
Anyone else having this issue? What did you do about it?
Haven't been to the dealer about it yet but will take it up on the first service.
It turned out to be the exhaust heat shield, which had come loose.
Dealer fixed it, no charge.
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MBWorld Fanatic!
Joined: Sep 2016
Posts: 1,718
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From: Australia
⏱️ 700HP Facelift converted C63 S Coupe with Drexler 3.06 plated LSD
yes i do get some rattle
just placed left/right side on each hole (3of them) 5gr/ml high temp copper grease and will report after few starts how it feels, thank you for the feedback
not sure when i bring in stealer for service if they do that at all because i never saw in the invoice grease charge or anything else or maybe is included in the service who knows haha
just placed left/right side on each hole (3of them) 5gr/ml high temp copper grease and will report after few starts how it feels, thank you for the feedback
not sure when i bring in stealer for service if they do that at all because i never saw in the invoice grease charge or anything else or maybe is included in the service who knows haha
How did you go with the copper grease?
Super Member
Joined: Nov 2022
Posts: 512
Likes: 86
From: Bulgaria
C43 AMG '17 / Stage II
i think have a bit better tone exhaust now when greased, will do it one more time in next few weeks/months, just don't understand how the grease change the rattle as when they're opened, it shouldn't cause any vibrations isnt it
or is because the spring inside?
Newbie
Joined: Aug 2024
Posts: 2
Likes: 1
C43, now C63
Just fixed my C63 with the death rattle completely free and in 2 hours.
tools needed, 8mm socket and knuckle joint
2 sets of grips
remove H pipe actuator from exhaust mounting, and remove the spring inside. If you have the rattle it will most likely be quite flat, remember the position of how it was situated in the actuator.
Now, stretch the spring so that it is more of a conical shape, rather than flat so that there is more resistance when pressing down on it.
Re install the spring and actuator on the exhaust and Bob’s your uncle, Fanny’s your aunt no more rattle.
I couldn’t believe Mercedes “engineers” wanted £6k for a new exhaust, and all it turned out to be was a over flattened actuator spring, which if you want to get a new one wouldn’t cost no more than £3.
mine now sounds awesome, more pops and bangs and sounds far better in higher rev range than before.
tools needed, 8mm socket and knuckle joint
2 sets of grips
remove H pipe actuator from exhaust mounting, and remove the spring inside. If you have the rattle it will most likely be quite flat, remember the position of how it was situated in the actuator.
Now, stretch the spring so that it is more of a conical shape, rather than flat so that there is more resistance when pressing down on it.
Re install the spring and actuator on the exhaust and Bob’s your uncle, Fanny’s your aunt no more rattle.
I couldn’t believe Mercedes “engineers” wanted £6k for a new exhaust, and all it turned out to be was a over flattened actuator spring, which if you want to get a new one wouldn’t cost no more than £3.
mine now sounds awesome, more pops and bangs and sounds far better in higher rev range than before.
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MBWorld God!
Joined: Dec 2019
Posts: 32,222
Likes: 6,279
Just fixed my C63 with the death rattle completely free and in 2 hours.
tools needed, 8mm socket and knuckle joint
2 sets of grips
remove H pipe actuator from exhaust mounting, and remove the spring inside. If you have the rattle it will most likely be quite flat, remember the position of how it was situated in the actuator.
Now, stretch the spring so that it is more of a conical shape, rather than flat so that there is more resistance when pressing down on it.
Re install the spring and actuator on the exhaust and Bob’s your uncle, Fanny’s your aunt no more rattle.
I couldn’t believe Mercedes “engineers” wanted £6k for a new exhaust, and all it turned out to be was a over flattened actuator spring, which if you want to get a new one wouldn’t cost no more than £3.
mine now sounds awesome, more pops and bangs and sounds far better in higher rev range than before.
tools needed, 8mm socket and knuckle joint
2 sets of grips
remove H pipe actuator from exhaust mounting, and remove the spring inside. If you have the rattle it will most likely be quite flat, remember the position of how it was situated in the actuator.
Now, stretch the spring so that it is more of a conical shape, rather than flat so that there is more resistance when pressing down on it.
Re install the spring and actuator on the exhaust and Bob’s your uncle, Fanny’s your aunt no more rattle.
I couldn’t believe Mercedes “engineers” wanted £6k for a new exhaust, and all it turned out to be was a over flattened actuator spring, which if you want to get a new one wouldn’t cost no more than £3.
mine now sounds awesome, more pops and bangs and sounds far better in higher rev range than before.
MBWorld Fanatic!
Joined: Sep 2016
Posts: 1,718
Likes: 608
From: Australia
⏱️ 700HP Facelift converted C63 S Coupe with Drexler 3.06 plated LSD
Just fixed my C63 with the death rattle completely free and in 2 hours.
tools needed, 8mm socket and knuckle joint
2 sets of grips
remove H pipe actuator from exhaust mounting, and remove the spring inside. If you have the rattle it will most likely be quite flat, remember the position of how it was situated in the actuator.
Now, stretch the spring so that it is more of a conical shape, rather than flat so that there is more resistance when pressing down on it.
Re install the spring and actuator on the exhaust and Bob’s your uncle, Fanny’s your aunt no more rattle.
I couldn’t believe Mercedes “engineers” wanted £6k for a new exhaust, and all it turned out to be was a over flattened actuator spring, which if you want to get a new one wouldn’t cost no more than £3.
mine now sounds awesome, more pops and bangs and sounds far better in higher rev range than before.
tools needed, 8mm socket and knuckle joint
2 sets of grips
remove H pipe actuator from exhaust mounting, and remove the spring inside. If you have the rattle it will most likely be quite flat, remember the position of how it was situated in the actuator.
Now, stretch the spring so that it is more of a conical shape, rather than flat so that there is more resistance when pressing down on it.
Re install the spring and actuator on the exhaust and Bob’s your uncle, Fanny’s your aunt no more rattle.
I couldn’t believe Mercedes “engineers” wanted £6k for a new exhaust, and all it turned out to be was a over flattened actuator spring, which if you want to get a new one wouldn’t cost no more than £3.
mine now sounds awesome, more pops and bangs and sounds far better in higher rev range than before.
MBWorld God!
Joined: Dec 2019
Posts: 32,222
Likes: 6,279
MBWorld God!
Joined: Dec 2019
Posts: 32,222
Likes: 6,279
MBWorld Fanatic!
Joined: Sep 2016
Posts: 1,718
Likes: 608
From: Australia
⏱️ 700HP Facelift converted C63 S Coupe with Drexler 3.06 plated LSD
Newbie
Joined: Dec 2025
Posts: 2
Likes: 0
C63s
2021 C63s Exhaust Rattle
have a 2021 C63s which is downpipe and tuned but cpc not done, recently my exhaust has been rattling and I swapped out the 3 actuators (2 rear 1 center) but the rattling hasn’t gone away I am thinking it is either the flaps that have failed, the mufflers, or valve module. If anyone has any solution please let me know. Noise comes from the center and rear.
Last edited by Stunnaboy63; Dec 23, 2025 at 05:49 PM.
Member
Joined: Jan 2024
Posts: 195
Likes: 58
From: Colorado
2018 C63S AMG Coupe, 2019 Jaguar F-Pace SVR
@Stunnaboy63 seems like you light have play in the "in and out movement" of the valve flap. The new actuators only affect the twisting action but not the in and out end play. The two fixes are to pack the underside of the actuator solenoid cup area with copper grease... The second is to stretch the spring so that it is more of a cone shape, rather than flat so it pushes in on the valve assembly when you re attach the actuator. The third (most unrealistic) fix is to replace the exhaust or at least the valve sections.
