Any idea what this noise this?
Thread Starter
Junior Member
Joined: May 2022
Posts: 27
Likes: 14
From: Los Angeles
'19 C63 Cabriolet
Any idea what this noise this?
Hi all. 2019 c63 cab here. Car was recently serviced and passed with flying colors. Runs great.
However, I have this very faint metallic ringing or squeaking noise that can be heard when I mount a mic on the bumper near the exhaust. In the car with the top up or down, you cannot hear the noise. Can only be heard in these mic recordings.
Conditions:
- can be heard on all drive modes
- louder and more sustained in sport+. In comfort it goes away much faster.
- only seems to happen at 3k rpm or higher and 50mph or faster
- blipping the throttle will make the noise flare up
- sound dies when off throttle and once the speed and/or rpm drops below what’s mentioned above
Video of sound here.
sound happens when I let off throttle and the car is cruising. I blip the throttle again mid cruise and the sound flares up, and slowly goes down again
What do you guys think? Any ideas?
However, I have this very faint metallic ringing or squeaking noise that can be heard when I mount a mic on the bumper near the exhaust. In the car with the top up or down, you cannot hear the noise. Can only be heard in these mic recordings.
Conditions:
- can be heard on all drive modes
- louder and more sustained in sport+. In comfort it goes away much faster.
- only seems to happen at 3k rpm or higher and 50mph or faster
- blipping the throttle will make the noise flare up
- sound dies when off throttle and once the speed and/or rpm drops below what’s mentioned above
Video of sound here.
sound happens when I let off throttle and the car is cruising. I blip the throttle again mid cruise and the sound flares up, and slowly goes down again
What do you guys think? Any ideas?
Last edited by jaydp; Jul 28, 2025 at 02:25 AM.
Super Member
Joined: Dec 2015
Posts: 609
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From: Suburban Maryland
2023 E 450 Sedan. 2018 GLC 300. 2013 E 350 Coupe (retired)
I think you discovered why mb does not recommend an external mic. Are you concerned by the 'crashing' sound? Is this normal gear change ruckus only privy to a bumper cam? I don't hear a ringing noise. Someone more knowledgeable will chime in.
Last edited by smiles201; Jul 28, 2025 at 02:12 AM.
Out Of Control!!
Joined: Nov 2018
Posts: 11,463
Likes: 5,354
From: San Francisco Bay Area
2019 C63CS
I've listened to the video a few times and I'm not sure what I'm supposed to hear. All I hear is exhaust pretty much. Having said that, I've never mounted a mic on the rear bumper, but there are moving parts back there. Your suspension is bouncing up and down, the valves inside of the dampers are continuously adjusting the damping, the rear differential actuator is adjusting the locking ratio of the diff constantly and the exhaust valves fully open above about 3k and partially close below. There's stuff going on in these cars and those things sometimes make noise. I agree with @PeterUbers , if you can't hear it w/o a mic near the source what are you trying to chase down? A likely normal noise that doesn't make it into the cabin?
Thread Starter
Junior Member
Joined: May 2022
Posts: 27
Likes: 14
From: Los Angeles
'19 C63 Cabriolet
To those asking why I put a mic if I can’t hear it in cabin or why I put a mic at all, it’s there because I intend on making car content. Good car sound does not come recording audio in cabin, it comes from mic’ing the car. All your favorite professional channels do this.
So for those wondering, the mic was not placed to diagnose the problem, but rather it found the problem.
Ive watched plenty of mic’d up cars, including c63, that DO NOT make this metallic sound.
The sound is definitely there as the issue was brought up to me by friends who I shared some videos with. Also shared the video when I went to service and they said they can hear the sound but are not sure where it’s coming from because underneath the car looks fine.
So for those wondering, the mic was not placed to diagnose the problem, but rather it found the problem.
Ive watched plenty of mic’d up cars, including c63, that DO NOT make this metallic sound.
The sound is definitely there as the issue was brought up to me by friends who I shared some videos with. Also shared the video when I went to service and they said they can hear the sound but are not sure where it’s coming from because underneath the car looks fine.
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Out Of Control!!
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2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
My best guess is that it's the exhaust vibrating - some component therein
get under there and see if anything replicates the sound with some gentle tapping
get under there and see if anything replicates the sound with some gentle tapping
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Thread Starter
Junior Member
Joined: May 2022
Posts: 27
Likes: 14
From: Los Angeles
'19 C63 Cabriolet
Thread Starter
Junior Member
Joined: May 2022
Posts: 27
Likes: 14
From: Los Angeles
'19 C63 Cabriolet
sound still persists…
Last edited by jaydp; Jul 28, 2025 at 10:42 AM.
Banned
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S65
Want a nice, silent car? Get an EV.
As far as postwhoring, I've been away at... a camp of sorts for the past 8 years. Gotta catch up on my post count.
Last edited by Sathinas; Jul 28, 2025 at 10:50 AM.
Thread Starter
Junior Member
Joined: May 2022
Posts: 27
Likes: 14
From: Los Angeles
'19 C63 Cabriolet
Seems you're looking for a solution to a problem that doesn't exist. It's a freaking car, with lots of turning and moving parts! I'm surprised you didn't put a microphone in the wheel well(s) and ask about that noise the tires make when driving at 70MPH, because your friends heard it from their car when they were next to you. I mean, what about that noisy thing thing in front of the windshield that makes more noise when you step on the accelerator? Have you considered installing a microphone under the hood as well?
Want a nice, silent car? Get an EV.
As far as postwhoring, I've been away at... a camp of sorts for the past 8 years. Gotta catch up on my post count.
Want a nice, silent car? Get an EV.
As far as postwhoring, I've been away at... a camp of sorts for the past 8 years. Gotta catch up on my post count.
get out my thread brother, you’re useless.
Out Of Control!!
Joined: Jun 2004
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2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
Something is resonating INside the exhaust then ... muffler ... just enough with the drop in rpm's to manifest - shy of a swap out of parts I'm not sure how this ends
oh and also check the tightness of all bolts from engine to mufflers ... down pipes etc. I've seen subtle mis torqued (loose) bolts causing this
heat shields? Are they properly pulled back from contact?
rotor/brake heat shields (if your car has them?) are they contacting or a bit too close?
is there anything loose in trunk? Spare wheel install hardware, wrenches etc? Inside the walls of the trunk are modules that are attached with bolts and I had a rattle from an xm radio box (baaaaack in the day) that gave this elusive noise until tightened down
oh and also check the tightness of all bolts from engine to mufflers ... down pipes etc. I've seen subtle mis torqued (loose) bolts causing this
heat shields? Are they properly pulled back from contact?
rotor/brake heat shields (if your car has them?) are they contacting or a bit too close?
is there anything loose in trunk? Spare wheel install hardware, wrenches etc? Inside the walls of the trunk are modules that are attached with bolts and I had a rattle from an xm radio box (baaaaack in the day) that gave this elusive noise until tightened down
Last edited by PeterUbers; Jul 28, 2025 at 12:00 PM.
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S65
Thread Starter
Junior Member
Joined: May 2022
Posts: 27
Likes: 14
From: Los Angeles
'19 C63 Cabriolet
Something is resonating INside the exhaust then ... muffler ... just enough with the drop in rpm's to manifest - shy of a swap out of parts I'm not sure how this ends
oh and also check the tightness of all bolts from engine to mufflers ... down pipes etc. I've seen subtle mis torqued (loose) bolts causing this
heat shields? Are they properly pulled back from contact?
rotor/brake heat shields (if your car has them?) are they contacting or a bit too close?
is there anything loose in trunk? Spare wheel install hardware, wrenches etc? Inside the walls of the trunk are modules that are attached with bolts and I had a rattle from an xm radio box (baaaaack in the day) that gave this elusive noise until tightened down
oh and also check the tightness of all bolts from engine to mufflers ... down pipes etc. I've seen subtle mis torqued (loose) bolts causing this
heat shields? Are they properly pulled back from contact?
rotor/brake heat shields (if your car has them?) are they contacting or a bit too close?
is there anything loose in trunk? Spare wheel install hardware, wrenches etc? Inside the walls of the trunk are modules that are attached with bolts and I had a rattle from an xm radio box (baaaaack in the day) that gave this elusive noise until tightened down
I feel like it is a sound resonating throughout the exhaust at this point. Is it possible it’s engine related and the sound is making its way out back through the exhaust?
you can hear the sound right? Lol
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*
In the video, I can't hear what you're describing and I am familiar with a mic mounted outside off the rear (for track-day video making) ... but it sounds like your mic is somewhat overloaded.
However, what you describe is similar to what my GTR Pro had ... metallic-like ping/ring within certain RPM ranges under load/throttle. In mine it was one of the exhaust valves and the entire exhaust was replaced under warranty. When the valves are such a (relatively) high-failure item, it seems strange that the engineers have stuck with an "all 1-piece system" as opposed to a design that would enable the valve to be replaced.
If you search the forum, you'll find that some people have opted to do various fixes for exhaust-system valve issues, including cut 'n weld approaches.
Although a different sound, on my C63 S, I also had a noise that occurred under load/throttle within an RPM range. In that case, as someone suggested, it turned out to be the exhaust system contacting a section of the heat-shield metal that had become slightly re-positioned. Sounds like your service people have eliminated this one. When you solve yours, it'd be interesting to know the conclusion.
However, what you describe is similar to what my GTR Pro had ... metallic-like ping/ring within certain RPM ranges under load/throttle. In mine it was one of the exhaust valves and the entire exhaust was replaced under warranty. When the valves are such a (relatively) high-failure item, it seems strange that the engineers have stuck with an "all 1-piece system" as opposed to a design that would enable the valve to be replaced.
If you search the forum, you'll find that some people have opted to do various fixes for exhaust-system valve issues, including cut 'n weld approaches.
Although a different sound, on my C63 S, I also had a noise that occurred under load/throttle within an RPM range. In that case, as someone suggested, it turned out to be the exhaust system contacting a section of the heat-shield metal that had become slightly re-positioned. Sounds like your service people have eliminated this one. When you solve yours, it'd be interesting to know the conclusion.
Out Of Control!!
Joined: Nov 2018
Posts: 11,463
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From: San Francisco Bay Area
2019 C63CS
I agree, the recording quality isn't very good. That mic is definitely overloaded. Even with headphones I can't hear what's being described and am rather distracted by the poor audio quality.
OP, you should request that they fit the chassis ears to isolate where the noise is coming from.
OP, you should request that they fit the chassis ears to isolate where the noise is coming from.
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
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2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
What the Benz mechanic says and what he actually did are often two totally different things, but you know that.
I hear the metallic rasp (faintly) in your clip and can understand that it's much more prevalent IRL while driving - it would prolly drive me nuts.
i highly doubt it's in the engine or turbo - those noises are different
Google turbo failing noises (loose turbo connections) and listen on YouTube - see if it sounds similar - those can be more prevalent during gearshifts
I hear the metallic rasp (faintly) in your clip and can understand that it's much more prevalent IRL while driving - it would prolly drive me nuts.
i highly doubt it's in the engine or turbo - those noises are different
Google turbo failing noises (loose turbo connections) and listen on YouTube - see if it sounds similar - those can be more prevalent during gearshifts
Thread Starter
Junior Member
Joined: May 2022
Posts: 27
Likes: 14
From: Los Angeles
'19 C63 Cabriolet
In the video, I can't hear what you're describing and I am familiar with a mic mounted outside off the rear (for track-day video making) ... but it sounds like your mic is somewhat overloaded.
However, what you describe is similar to what my GTR Pro had ... metallic-like ping/ring within certain RPM ranges under load/throttle. In mine it was one of the exhaust valves and the entire exhaust was replaced under warranty. When the valves are such a (relatively) high-failure item, it seems strange that the engineers have stuck with an "all 1-piece system" as opposed to a design that would enable the valve to be replaced.
If you search the forum, you'll find that some people have opted to do various fixes for exhaust-system valve issues, including cut 'n weld approaches.
Although a different sound, on my C63 S, I also had a noise that occurred under load/throttle within an RPM range. In that case, as someone suggested, it turned out to be the exhaust system contacting a section of the heat-shield metal that had become slightly re-positioned. Sounds like your service people have eliminated this one. When you solve yours, it'd be interesting to know the conclusion.
However, what you describe is similar to what my GTR Pro had ... metallic-like ping/ring within certain RPM ranges under load/throttle. In mine it was one of the exhaust valves and the entire exhaust was replaced under warranty. When the valves are such a (relatively) high-failure item, it seems strange that the engineers have stuck with an "all 1-piece system" as opposed to a design that would enable the valve to be replaced.
If you search the forum, you'll find that some people have opted to do various fixes for exhaust-system valve issues, including cut 'n weld approaches.
Although a different sound, on my C63 S, I also had a noise that occurred under load/throttle within an RPM range. In that case, as someone suggested, it turned out to be the exhaust system contacting a section of the heat-shield metal that had become slightly re-positioned. Sounds like your service people have eliminated this one. When you solve yours, it'd be interesting to know the conclusion.
my service guy said it’s probably the active exhaust which is why I already attempted to fix it going under the car, inspecting it, and spraying moving areas with silicone lubricant.
now I’m hearing from you guys it’s likely exhaust. All signs are pointing at exhaust so I guess I need to look deeper.
Thread Starter
Junior Member
Joined: May 2022
Posts: 27
Likes: 14
From: Los Angeles
'19 C63 Cabriolet
Thread Starter
Junior Member
Joined: May 2022
Posts: 27
Likes: 14
From: Los Angeles
'19 C63 Cabriolet
What the Benz mechanic says and what he actually did are often two totally different things, but you know that.
I hear the metallic rasp (faintly) in your clip and can understand that it's much more prevalent IRL while driving - it would prolly drive me nuts.
i highly doubt it's in the engine or turbo - those noises are different
Google turbo failing noises (loose turbo connections) and listen on YouTube - see if it sounds similar - those can be more prevalent during gearshifts
I hear the metallic rasp (faintly) in your clip and can understand that it's much more prevalent IRL while driving - it would prolly drive me nuts.
i highly doubt it's in the engine or turbo - those noises are different
Google turbo failing noises (loose turbo connections) and listen on YouTube - see if it sounds similar - those can be more prevalent during gearshifts
Thank you for the help. Good to know it probably is not rooted at the front of the car
Member
Joined: Jan 2024
Posts: 201
Likes: 60
From: Colorado
2018 C63S AMG Coupe, 2019 Jaguar F-Pace SVR
I still don't hear it. The sound in your video is over-modulated, or my awesome Dell laptop speakers just can handle the power. Maybe not your rear exhaust valves, BUT... There's a TON of threads about the rattling 3rd active exhaust valve that is in the center of the H-pipe section. Perhaps that is what you are hearing. Some people have reported success in reducing the noise by packing enough copper grease between the servo motor and the backing plate that the valve can't rattle around anymore. Some people just take off the servo, put a valve simulator in the plug, and tack-weld the valve in the open position.
Thread Starter
Junior Member
Joined: May 2022
Posts: 27
Likes: 14
From: Los Angeles
'19 C63 Cabriolet
I still don't hear it. The sound in your video is over-modulated, or my awesome Dell laptop speakers just can handle the power. Maybe not your rear exhaust valves, BUT... There's a TON of threads about the rattling 3rd active exhaust valve that is in the center of the H-pipe section. Perhaps that is what you are hearing. Some people have reported success in reducing the noise by packing enough copper grease between the servo motor and the backing plate that the valve can't rattle around anymore. Some people just take off the servo, put a valve simulator in the plug, and tack-weld the valve in the open position.
Member
Joined: Jan 2024
Posts: 201
Likes: 60
From: Colorado
2018 C63S AMG Coupe, 2019 Jaguar F-Pace SVR
. I was just trying to help even though your over-modulated video doesn't play it clearly. Do I know the exact configuration of every iteration of the W205... No. But I do own one, and it has the "performance exhaust", and it has the "third valve", and I've read numerous threads on the metallic rattling sound being caused by that third valve.
MBWorld Fanatic!
Joined: Feb 2017
Posts: 1,126
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Final Edition C63s / RS3 Sportback
Hi all. 2019 c63 cab here. Car was recently serviced and passed with flying colors. Runs great.
However, I have this very faint metallic ringing or squeaking noise that can be heard when I mount a mic on the bumper near the exhaust. In the car with the top up or down, you cannot hear the noise. Can only be heard in these mic recordings.
Conditions:
- can be heard on all drive modes
- louder and more sustained in sport+. In comfort it goes away much faster.
- only seems to happen at 3k rpm or higher and 50mph or faster
- blipping the throttle will make the noise flare up
- sound dies when off throttle and once the speed and/or rpm drops below what’s mentioned above
Video of sound here.
sound happens when I let off throttle and the car is cruising. I blip the throttle again mid cruise and the sound flares up, and slowly goes down again
https://youtube.com/shorts/5nGZ5q1Wv...V-tdkO-Q2amkiO
What do you guys think? Any ideas?
However, I have this very faint metallic ringing or squeaking noise that can be heard when I mount a mic on the bumper near the exhaust. In the car with the top up or down, you cannot hear the noise. Can only be heard in these mic recordings.
Conditions:
- can be heard on all drive modes
- louder and more sustained in sport+. In comfort it goes away much faster.
- only seems to happen at 3k rpm or higher and 50mph or faster
- blipping the throttle will make the noise flare up
- sound dies when off throttle and once the speed and/or rpm drops below what’s mentioned above
Video of sound here.
sound happens when I let off throttle and the car is cruising. I blip the throttle again mid cruise and the sound flares up, and slowly goes down again
https://youtube.com/shorts/5nGZ5q1Wv...V-tdkO-Q2amkiO
What do you guys think? Any ideas?
