W205C43PFL

The noise Jimmy_c63s and George_1992 experienced is similar to what us C43 owners experienced:
https://mbworld.org/forums/c450-c43-...-thoughts.html
I also heard this noise on a 2019 E450, given the hardware differences with the C63s rear diff and the C43, I doubt this is the cause. If you want to take it to the dealership, tell them to put the car in dyno mode on a hoist and the noise is easily reproduced (as if or not they say it is normal, it is up to the dealership) (that being said, this only applies if the noise is coming from your rear diff like us C43 guys)

George_1992

Thanks buddy.......... gosh just another issue to deal with.......... so when you say you heard the noise on a E450 was that a loaner car or brand new?

Sounds identical to described in the C43 topic!! It confuses me cos some other C43 guys saying they changed their diff and the noise was still there 😟😟😟

W205C43PFL

Yup. That car was brand spanking new with only few KMs on it, it was not as loud as my C43 but that was probably because of the sound insulation in the E-Class but I am not surprised it would be louder after break-in.

I didn't test it with windows down however. I too was dealing with this on my C43, the noise is still present on my car after one rear diff replacement. The dealership I worked with refused to work with me further so I just accepted this as something "normal". I guess when you think of it as a characteristic of your car you would feel better, reminding you that you didn't get the base C300.

As for others posted there, there was one that had the differential replaced for 5 times or so before ending up with one that has no noise.

I forgot to mention, I also test drove a 2020 C43 and it too have this problem because at one point I was deciding if I should get a facelift.

Here is another thread but this time facelift (although OP in that thread describes a different problem alongside this problem he faces)
https://mbworld.org/forums/c450-c43-...ise-issue.html

munis

I know what noise you are talking about. But in my case, it does not happen on lift off. It happens when I actually press the brakes at 60mph and there is an weight transfer to the front. The noise matches bang on with what you are describing.

But here is the thing, my car never made that noise before my first track day. This started after a track day for me. So I kind off thought that is the front tires that are making this sound. It almost sounds like a bad wheel bearing, but then again a bad wheel bearing will while all the time at all speeds, and the whine will actually get progressively worse with time.

Also this sound comes from the front 100%, so I would not put it on the differential. I got this sound for a couple of days after my track day and now it is totally gone again.

George_1992

Thanks you 2 for replying this topic..........

I read through that C43 topic and seems the only thing that fixed it was a specially balanced drive shaft huh.......... man i guess I can live with it as long as the car doesn't blow up and leave me stranded

Munis that is weird. Not sure why that happened to you haha but glad it's gone. Did yours sound like blowing over a bottle top too? 🤔🤔🤔

W205C43PFL

Thanks for your follow up, I believe they were two different problems, the vibration and the sound you were describing was the driveshaft being imbalanced, the other sound when you left off throttle and cruising (the best way to produce it was setting cruise control to those speeds) was solved by replacing the rear diff which was described in the 2017 thread: https://mbworld.org/forums/c450-c43-...-thoughts.html

magicve17

Here is an used 2019 CLS AMG53 owner, and mine does similar thing.

Accelerate to above 40mph, ideally 50, 60, then release the gas pedal.
Ideally, a downhill road+slightly turn left, those conditions combined makes the noise most noticeable.

The noise frequency is like "Ooo...Ooo...Ooo..." and the lasting and interval of "Ooo..." is highly related to speed. So when I release the gas pedal, the car slows down gradually, the frequency also changes accordingly. It disappears under 35mph.
Sometimes I could even feel subtle vibration with the noise. Some people describe it as "Engine brake noise", that's exactly how I feel it.

I'm so frustrated, anyone got any idea if there is any solution for this? Took the car to the dealer 3 times already

hypnomo

ive got exactly the same problem withj pre-facelift. Did you find anything on this?

Jimmy_c63s

Thanks for bumping the thread I forgot to update. Its "apparently" the rear diff. I've done 3 diff oil changes and no change in sound, still there. Mercedes tech diagnosed it as the electronic diff.

Some of our cars make this noise, others don't. Either way, it's nothing to worry about mate, just a characteristic and it will not cause a problem.

I've had this noise since brand new and my car will be 7 years old in September.

Jimmy_c63s

A full differential rebuild later plus a Drexler LSD installed and this whine is still present in my C63 Coupe.

So if anyone else has this noise PLEASE don't shell out on a new diff just yet.

Once again the noise for me is present at 70kmh to 74kmh AND 110kmh to 112kmh when foot is on the throttle or coasting (as long as I'm at those exact speeds). No other times.

It's got to be driveline related and it's harmless but can get on your nerves every once in a while...

That's my update.

hypnomo

Still on the same problem. Exactly same speed like yours.

MB Germany says it is known and a new differential is no guarantee that the problem is solved they said. Also changing drivetrain could also help a bit.. Don't know.

Living with it at the moment.

What tires are you on?

Jimmy_c63s

Changing the drivetrain! What parts of the drivetrain are they talking about getting changed? Prop shaft? Axles? It would be nice that they could give us some details or a bulletin about it.

Gets on my nerves yet at times it doesn't seem as loud but other times it's noticeable. I'm on stock sized coupe tires Michelin PS4S (255-35-19 front and 285-30-20 rears)

Does yours sound faint? Like a slight hooo sound at those speeds?

hypnomo

Hey 😄

Strange that we exactly share the same problem at same speeds 😄

Yes it makes a hoo hoo sound. And I've got also ps4s with same sizes and 20s rear.

Do you have the Mercedes gtr alloy wheels?

BTW : it is louder on the passenger seat to hear.

I can really feel your pain. Maybe it's something completely different?

😄

Jimmy_c63s

Yes man haha AMG GTR wheels I have.

Yes it's also from that direction I hear it more from the rear passenger seat side when I am driving 😂

How funny we have the exact same sound. I will try to record it this weekend and post the sound it's just very faint to record. Then we can 100% confirm we are wooo brothers

George_1992

5 year update - same sound still present on my C63s coupe. Do you still have your car? Is it still making this noise? Mine..... well i still SAME SOUND after 5 years. As mentioned earlier the sound is identical to blowing over a bottle top but the volume is much more faint

stock_c63s

anyone know what this could be???

Jimmy_c63s

Hey man sorry but that's nothing to do with this topic, that's your exhaust flap(s). Please help us out by keeping it on topic (that's not the whining sound we are trying to figure out).

stock_c63s

what effects does a bad exhaust flap have on the car? Limp mode? Check engine light?

George_1992

Shhh man

Jimmy_c63s

Are you still around mate or did you throw in the towel....

Anyone else have any ideas or experienced this exact same sound on their C63's?

A very faint hooo sound that sounds like someone's blowing the top of a bottle? 70kmh and 110kmh is when it happens on my car