c43 unexpected Noise when gently applying throttle
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c43
c43 unexpected Noise when gently applying throttle
Hi All,
I recently got a c43 (2020 model) in the US. The car is super fun to drive and have been enjoying it, this being my first MB. At around 800 mile mark, on the way back from work I heard a booming noise while gently applying throttle to maintain speed. It was probably around 55 to 60mph. As soon as I let of the gas, the noise stopped. This continue for a bit and then when I switched to sport+ and then back, it seemed to go away. I then drove the car for 30 mins and didnt hear it. I then heard it again a few days later when driving during the day and it went away after a while. Then yesterday evening again on the way back form work I could hear the noise while gently applying the throttle. And it seems to reduce at higher speeds. Today morning when I drove didnt have any issues. I have seen an thread around rear diff problems here. Could this be related to it? Anything I need to look for. Can cold weather cause any problems as I see the issue more in the evenings then day times. The temperatures are not terribly cold (40 to 45 F). The noise is hard to miss now that I can see the difference between when it is there and when it is not there.
Any thoughts.
I recently got a c43 (2020 model) in the US. The car is super fun to drive and have been enjoying it, this being my first MB. At around 800 mile mark, on the way back from work I heard a booming noise while gently applying throttle to maintain speed. It was probably around 55 to 60mph. As soon as I let of the gas, the noise stopped. This continue for a bit and then when I switched to sport+ and then back, it seemed to go away. I then drove the car for 30 mins and didnt hear it. I then heard it again a few days later when driving during the day and it went away after a while. Then yesterday evening again on the way back form work I could hear the noise while gently applying the throttle. And it seems to reduce at higher speeds. Today morning when I drove didnt have any issues. I have seen an thread around rear diff problems here. Could this be related to it? Anything I need to look for. Can cold weather cause any problems as I see the issue more in the evenings then day times. The temperatures are not terribly cold (40 to 45 F). The noise is hard to miss now that I can see the difference between when it is there and when it is not there.
Any thoughts.
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Joined: Dec 2016
Posts: 797
Likes: 141
2018 C43
Hi All,
I recently got a c43 (2020 model) in the US. The car is super fun to drive and have been enjoying it, this being my first MB. At around 800 mile mark, on the way back from work I heard a booming noise while gently applying throttle to maintain speed. It was probably around 55 to 60mph. As soon as I let of the gas, the noise stopped. This continue for a bit and then when I switched to sport+ and then back, it seemed to go away. I then drove the car for 30 mins and didnt hear it. I then heard it again a few days later when driving during the day and it went away after a while. Then yesterday evening again on the way back form work I could hear the noise while gently applying the throttle. And it seems to reduce at higher speeds. Today morning when I drove didnt have any issues. I have seen an thread around rear diff problems here. Could this be related to it? Anything I need to look for. Can cold weather cause any problems as I see the issue more in the evenings then day times. The temperatures are not terribly cold (40 to 45 F). The noise is hard to miss now that I can see the difference between when it is there and when it is not there.
Any thoughts.
I recently got a c43 (2020 model) in the US. The car is super fun to drive and have been enjoying it, this being my first MB. At around 800 mile mark, on the way back from work I heard a booming noise while gently applying throttle to maintain speed. It was probably around 55 to 60mph. As soon as I let of the gas, the noise stopped. This continue for a bit and then when I switched to sport+ and then back, it seemed to go away. I then drove the car for 30 mins and didnt hear it. I then heard it again a few days later when driving during the day and it went away after a while. Then yesterday evening again on the way back form work I could hear the noise while gently applying the throttle. And it seems to reduce at higher speeds. Today morning when I drove didnt have any issues. I have seen an thread around rear diff problems here. Could this be related to it? Anything I need to look for. Can cold weather cause any problems as I see the issue more in the evenings then day times. The temperatures are not terribly cold (40 to 45 F). The noise is hard to miss now that I can see the difference between when it is there and when it is not there.
Any thoughts.
If you can get multiple recordings on various days, you will have better chance.
The diff noise is like weird humming bad ground feedback from speakers at certain speed like 80kmh or 50mph. Havent heard any reoccurring booming noises.
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c43
I had the same sound coming today evening when driving back. Near my home I decided to drive around the neighborhood at slower speeds to see if I can find anything with the sounds. I finally got a consistent steps: The sound seems to come at rpm between 1000 and 1500. Once it crosses that it doesn't come. I found this when I switched to manual mode. In manual mode since the revs are held higher for the lower gears consistently above 2k, I didn't hear any sound until I dropped down to 6 or 7 and the rpm dropped closer to 1500. In comfort mode it is very pronounced when I just want to keep slower speeds. Sport+ helps a bit as the rpm is a bit higher there as well. I drove around for a bit and can consistently reproduce the behavior.
Does the transmission adapt as we drive? When I leave work I drive in a parking lot at slow speeds before getting out, but when I leave from home, I hit higher speeds fairly quickly.
Any thoughts on what this could mean?
Does the transmission adapt as we drive? When I leave work I drive in a parking lot at slow speeds before getting out, but when I leave from home, I hit higher speeds fairly quickly.
Any thoughts on what this could mean?
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Sorry that you are experiencing such an issue with a brand new vehicle. I am also not sure what do you mean by booming sound, does it sound like firework or a cannon?
Come to think of it, I recently heard a new noise when gently applying throttle too (2017 C43), but the noise only happens between gears (so after it shifts, it makes the noise and then immediately disappears) It happens when slowly accelerating in Eco Mode and Comfort Mode and the sound is most noticeable when engine shifts between 1500 RPM and 2000 RPM. In between gear 2 to gear 3 and then in between gear 4 to gear 5. Sound is not present at all when the engine shifts higher than 2000 RPM.
Since OP's noise is constant even after gear shifts, the sound I am experiencing might be something totally different.
I can't really describe the sound I am experiencing either, but it sounded like something coming from the exhaust more than a transmission or maybe ... *I'm just hearing it wrong* and that the sound is from a completely different location so transmission can not be ruled out. But it really didn't sound like it is coming from the front of the vehicle. Initially thought it was the wastegate but then realized the sound is completely different to what was posted on this forum. The sound ONLY appears when the vehicle is warm.
The closest I can refer to the sound is a slight mechanical scratching sound (this description might not be close to accurate at all).
I am wondering if anyone have an idea or speculation based on this limited information I provided? I wouldn't be able to get this checked as my winters are still on and on top of that, COVID-19, mb dealerships are closed.
Come to think of it, I recently heard a new noise when gently applying throttle too (2017 C43), but the noise only happens between gears (so after it shifts, it makes the noise and then immediately disappears) It happens when slowly accelerating in Eco Mode and Comfort Mode and the sound is most noticeable when engine shifts between 1500 RPM and 2000 RPM. In between gear 2 to gear 3 and then in between gear 4 to gear 5. Sound is not present at all when the engine shifts higher than 2000 RPM.
Since OP's noise is constant even after gear shifts, the sound I am experiencing might be something totally different.
I can't really describe the sound I am experiencing either, but it sounded like something coming from the exhaust more than a transmission or maybe ... *I'm just hearing it wrong* and that the sound is from a completely different location so transmission can not be ruled out. But it really didn't sound like it is coming from the front of the vehicle. Initially thought it was the wastegate but then realized the sound is completely different to what was posted on this forum. The sound ONLY appears when the vehicle is warm.
The closest I can refer to the sound is a slight mechanical scratching sound (this description might not be close to accurate at all).
I am wondering if anyone have an idea or speculation based on this limited information I provided? I wouldn't be able to get this checked as my winters are still on and on top of that, COVID-19, mb dealerships are closed.
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c43
I think I found what the problem was. On highways I was usually driving on sport+, but one day I drove in Comfort mode as I read during the breakin they recommended driving in C. So thats when I noticed this sound. After my experiments last two days, I realize that the sound is the one that happens when trying accelerate in a gear above where I should. What was happening is that in Comfort mode since we get to 9th pretty quick, when you barely apply throttle, the gear doesnt drop down to increase the revs. I barely put any pressure on the throttle so transmission doesnt change the gear. But if I press it a bit more, it drops down to the right gear and revs go up. So in 9th if the revs stay below 1500 this happens. Or even for a few other gears. So today I went for a ride and figured out the correct pressure to ensure that transmission recognizes that I am trying to accelerate.
In sport+ mode, since gears are aggressive, this wasnt an issue. In manual this wasnt a problem and when In 9th I dropped to 8th when I wanted to accelerate a bit. Its possible in comfort mode in slower speeds while driving around the neighborhood I probably didnt hear the sound as I usually have a bit louder music. After driving in manual, I feel like 7 gears gave an optimal experience versus the 9.
So is this something I need to check out as I drove this way in the incorrect gear only two or three times?
In the drive today I finally got a very good feel for the car and gearing and back to enjoying the drive.
In sport+ mode, since gears are aggressive, this wasnt an issue. In manual this wasnt a problem and when In 9th I dropped to 8th when I wanted to accelerate a bit. Its possible in comfort mode in slower speeds while driving around the neighborhood I probably didnt hear the sound as I usually have a bit louder music. After driving in manual, I feel like 7 gears gave an optimal experience versus the 9.
So is this something I need to check out as I drove this way in the incorrect gear only two or three times?
In the drive today I finally got a very good feel for the car and gearing and back to enjoying the drive.
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Super Member
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From: Sydney
2015 E400 Coupe
This why the cars have warranty and MB has service technicians. Take it in, even if they can't hear it they will record the issue and test drive it. Get them to give you a report in writing.
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C190
I really don’t understand what you mean about the sound and rpm/gear selection - I can’t fathom what kind of sound that could be. How about auto mode. If you drove in auto mode would the gear be wrong and you get the sound too?
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I never mention the gear being wrong so likely you are talking to OP and not me. If that's the case just ignore me lol.
Last edited by W205C43PFL; Mar 19, 2020 at 05:33 PM.
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c43
I might have used the wrong choice of word to describe the sound "Booming" and I guess that was misleading. So apologies for that. I would equate it to the sound that you hear when there is a wheel bearing issue but not as intense. I also talked to the dealer and explained and would take it in once the covid situation settles down a bit.
I have a family car which is a Audi q5 and havent driven it for a while since getting the c43. So today I decided to drive that and check the rpm/throttle response. It doesnt have any sport packages. I drove it and got to the same rpm range (1500-1750) and when I gently apply the pressure to just keep the speed, i heard the same sound, just a little fainter. The q5 is 8 speed. So it seems like the throttle sensitivity on the comfort mode doesnt down shift fast enough when bare minimum pressure is applied to keep the vehicle in constant speed. Sport+ gears stay lower so rpms are mostly close to 2000. In comfort I either need to apply throttle a bit higher or I use paddle to down shift and then the sound disappears.
It could also be the back pressure noise that alexasa mentioned. Since I have the PE I pay more attention to how things sound and thats why I noticed this.
I havent been into the technical details of cars for a while until I researched c43 and buying it. So I am just trying to learning these things as well. One video I saw about low rpm/ lugging and also LSPI was interesting.
At this point a I am sticking mostly to drive it on sport+ or manual. The fuel economy might be down, but I guess I didnt buy c43 for the fuel economy
I have a family car which is a Audi q5 and havent driven it for a while since getting the c43. So today I decided to drive that and check the rpm/throttle response. It doesnt have any sport packages. I drove it and got to the same rpm range (1500-1750) and when I gently apply the pressure to just keep the speed, i heard the same sound, just a little fainter. The q5 is 8 speed. So it seems like the throttle sensitivity on the comfort mode doesnt down shift fast enough when bare minimum pressure is applied to keep the vehicle in constant speed. Sport+ gears stay lower so rpms are mostly close to 2000. In comfort I either need to apply throttle a bit higher or I use paddle to down shift and then the sound disappears.
It could also be the back pressure noise that alexasa mentioned. Since I have the PE I pay more attention to how things sound and thats why I noticed this.
I havent been into the technical details of cars for a while until I researched c43 and buying it. So I am just trying to learning these things as well. One video I saw about low rpm/ lugging and also LSPI was interesting.
At this point a I am sticking mostly to drive it on sport+ or manual. The fuel economy might be down, but I guess I didnt buy c43 for the fuel economy
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C43AMG
Sorry that you are experiencing such an issue with a brand new vehicle. I am also not sure what do you mean by booming sound, does it sound like firework or a cannon?
Come to think of it, I recently heard a new noise when gently applying throttle too (2017 C43), but the noise only happens between gears (so after it shifts, it makes the noise and then immediately disappears) It happens when slowly accelerating in Eco Mode and Comfort Mode and the sound is most noticeable when engine shifts between 1500 RPM and 2000 RPM. In between gear 2 to gear 3 and then in between gear 4 to gear 5. Sound is not present at all when the engine shifts higher than 2000 RPM.
Since OP's noise is constant even after gear shifts, the sound I am experiencing might be something totally different.
I can't really describe the sound I am experiencing either, but it sounded like something coming from the exhaust more than a transmission or maybe ... *I'm just hearing it wrong* and that the sound is from a completely different location so transmission can not be ruled out. But it really didn't sound like it is coming from the front of the vehicle. Initially thought it was the wastegate but then realized the sound is completely different to what was posted on this forum. The sound ONLY appears when the vehicle is warm.
The closest I can refer to the sound is a slight mechanical scratching sound (this description might not be close to accurate at all).
I am wondering if anyone have an idea or speculation based on this limited information I provided? I wouldn't be able to get this checked as my winters are still on and on top of that, COVID-19, mb dealerships are closed.
Come to think of it, I recently heard a new noise when gently applying throttle too (2017 C43), but the noise only happens between gears (so after it shifts, it makes the noise and then immediately disappears) It happens when slowly accelerating in Eco Mode and Comfort Mode and the sound is most noticeable when engine shifts between 1500 RPM and 2000 RPM. In between gear 2 to gear 3 and then in between gear 4 to gear 5. Sound is not present at all when the engine shifts higher than 2000 RPM.
Since OP's noise is constant even after gear shifts, the sound I am experiencing might be something totally different.
I can't really describe the sound I am experiencing either, but it sounded like something coming from the exhaust more than a transmission or maybe ... *I'm just hearing it wrong* and that the sound is from a completely different location so transmission can not be ruled out. But it really didn't sound like it is coming from the front of the vehicle. Initially thought it was the wastegate but then realized the sound is completely different to what was posted on this forum. The sound ONLY appears when the vehicle is warm.
The closest I can refer to the sound is a slight mechanical scratching sound (this description might not be close to accurate at all).
I am wondering if anyone have an idea or speculation based on this limited information I provided? I wouldn't be able to get this checked as my winters are still on and on top of that, COVID-19, mb dealerships are closed.
MBWorld God!
Joined: Dec 2019
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Sorry to hear about that, do you have a video clip on this? I don't think I have the sound anymore on my vehicle so that was strange. To add to the confusion (which is awkward since I was the one that mentioned about the sound in the post you quoted), I don't even remember what I was hearing back in 2020.
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C43AMG
Car is at Mercedes at the moment and I took shoo foreman for a ride this morning to show it… he said it is the rear differential..
3 weeks ago we replaced bad engine mounts and check trans mounts… it’s only when applying gas very light. Happens in C,S and S+…
you can feel and hear it very easy when sitting in the car.
3 weeks ago we replaced bad engine mounts and check trans mounts… it’s only when applying gas very light. Happens in C,S and S+…
you can feel and hear it very easy when sitting in the car.
MBWorld God!
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Car is at Mercedes at the moment and I took shoo foreman for a ride this morning to show it… he said it is the rear differential..
3 weeks ago we replaced bad engine mounts and check trans mounts… it’s only when applying gas very light. Happens in C,S and S+…
you can feel and hear it very easy when sitting in the car.
3 weeks ago we replaced bad engine mounts and check trans mounts… it’s only when applying gas very light. Happens in C,S and S+…
you can feel and hear it very easy when sitting in the car.
https://mbworld.org/forums/c450-c43-...-thoughts.html
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From: Central Ohio
2017 C43, 1966 230SL, 2006 Jeep Rubicon
@Merl86 Thanks for posting that video!!! Now I know what to listen for. Sounds like a bass guitar strumming over and over. I can understand why a few people described it as booming.
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C43AMG
@Merl86 Thanks for posting that video!!! Now I know what to listen for. Sounds like a bass guitar strumming over and over. I can understand why a few people described it as booming.
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C43AMG
@Merl86 Thanks for posting that video!!! Now I know what to listen for. Sounds like a bass guitar strumming over and over. I can understand why a few people described it as booming.
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https://mbworld.org/forums/c450-c43-...bration-i.html
https://mbworld.org/forums/c450-c43-...-thoughts.html
Edit: Here are some more:
https://mbworld.org/forums/c450-c43-...ise-issue.html
https://mbworld.org/forums/c450-c43-...igh-speed.html
As you can tell if the rear differential isn't the only one that fixes your problem, the driveshaft might be something you want to look at next.
Edit 2: not C 43, C 300 actually this time: https://mbworld.org/forums/c-class-w...ml#post7104051
Last edited by W205C43PFL; Nov 9, 2022 at 07:17 AM.
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C43 AMG W205
Weird sound gearing on low RPM
Sorry that you are experiencing such an issue with a brand new vehicle. I am also not sure what do you mean by booming sound, does it sound like firework or a cannon?
Come to think of it, I recently heard a new noise when gently applying throttle too (2017 C43), but the noise only happens between gears (so after it shifts, it makes the noise and then immediately disappears) It happens when slowly accelerating in Eco Mode and Comfort Mode and the sound is most noticeable when engine shifts between 1500 RPM and 2000 RPM. In between gear 2 to gear 3 and then in between gear 4 to gear 5. Sound is not present at all when the engine shifts higher than 2000 RPM.
Since OP's noise is constant even after gear shifts, the sound I am experiencing might be something totally different.
I can't really describe the sound I am experiencing either, but it sounded like something coming from the exhaust more than a transmission or maybe ... *I'm just hearing it wrong* and that the sound is from a completely different location so transmission can not be ruled out. But it really didn't sound like it is coming from the front of the vehicle. Initially thought it was the wastegate but then realized the sound is completely different to what was posted on this forum. The sound ONLY appears when the vehicle is warm.
The closest I can refer to the sound is a slight mechanical scratching sound (this description might not be close to accurate at all).
I am wondering if anyone have an idea or speculation based on this limited information I provided? I wouldn't be able to get this checked as my winters are still on and on top of that, COVID-19, mb dealerships are closed.
Come to think of it, I recently heard a new noise when gently applying throttle too (2017 C43), but the noise only happens between gears (so after it shifts, it makes the noise and then immediately disappears) It happens when slowly accelerating in Eco Mode and Comfort Mode and the sound is most noticeable when engine shifts between 1500 RPM and 2000 RPM. In between gear 2 to gear 3 and then in between gear 4 to gear 5. Sound is not present at all when the engine shifts higher than 2000 RPM.
Since OP's noise is constant even after gear shifts, the sound I am experiencing might be something totally different.
I can't really describe the sound I am experiencing either, but it sounded like something coming from the exhaust more than a transmission or maybe ... *I'm just hearing it wrong* and that the sound is from a completely different location so transmission can not be ruled out. But it really didn't sound like it is coming from the front of the vehicle. Initially thought it was the wastegate but then realized the sound is completely different to what was posted on this forum. The sound ONLY appears when the vehicle is warm.
The closest I can refer to the sound is a slight mechanical scratching sound (this description might not be close to accurate at all).
I am wondering if anyone have an idea or speculation based on this limited information I provided? I wouldn't be able to get this checked as my winters are still on and on top of that, COVID-19, mb dealerships are closed.
I have C43 Amg W205 year 2020 and same sound appears when I'm shifting 4 to 5th gear at low rpm. Noise disappears when I accelerate harder on higher rpm. And it also does it only with warm engine / transmission.
It's weird as it is there and then it's not ...🧐
Please let me know if you figure out where your sound came from ?
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I have C43 Amg W205 year 2020 and same sound appears when I'm shifting 4 to 5th gear at low rpm. Noise disappears when I accelerate harder on higher rpm. And it also does it only with warm engine / transmission.
It's weird as it is there and then it's not ...🧐
Please let me know if you figure out where your sound came from ?
It's weird as it is there and then it's not ...🧐
Please let me know if you figure out where your sound came from ?
As strange for me however, it disappeared, now I am getting a ticking sound when the transmission upshifts, here are some videos https://drive.google.com/drive/folde...P81fC7xyyG15Wt and a whining sound when shifting from Park to Drive or Park to Reverse, it sounds similar/or exact to the sound you put the vehicle in Park, does your vehicle also makes this noise when you put in Park? It is the Parking pawl and the mechanism engaging right? Here is that video (you can hear both the tick sound when shifting to Park and the whining when shifting from Park to Drive and Park to Reverse https://drive.google.com/file/d/1Mi4...PIW6bJhyK/view
Back to your sound, does it happen only when it is dry and not humid conditions like the sound I previously experienced back in 2020 or so? If you have any idea of what is the sound I am experiencing as well, please do comment, thanks! Sorry that you posted and I ended up asking you for help as well. Hopefully you can capture your sound on camera and I can help you figure it out as well.
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C43 AMG W205
Thanks for replying.
Humidity does not make difference. I have absolutely no idea what does...well it usually doesn't appear when transmission is cold but when it gets approx. 60 C it starts. And even then sometimes it doesn't appear.
Yeah I did capture it to my camera today...sound is not very clear but can be heard.
I tried to upload it but I am so ****ty to use these platforms 😓
Anyway if I manage to upload file the sound starts around 5 second from beginning.
I tried to listen your footage...both of them but I didn't catch any weird ticking noice. Maybe I just don't know what to listen 😕
Humidity does not make difference. I have absolutely no idea what does...well it usually doesn't appear when transmission is cold but when it gets approx. 60 C it starts. And even then sometimes it doesn't appear.
Yeah I did capture it to my camera today...sound is not very clear but can be heard.
I tried to upload it but I am so ****ty to use these platforms 😓
Anyway if I manage to upload file the sound starts around 5 second from beginning.
I tried to listen your footage...both of them but I didn't catch any weird ticking noice. Maybe I just don't know what to listen 😕
