GWSHARK: Here's my update: I'm still feeling the same vibration. I just had it in last week to check this vibration again: shop foreman himself kept it overnight and test drove on highway. He said he could also feel it. He re-balanced all wheels and checked for out-of-round rims and/or damaged tires. Results: wheels were not out of balance (but re-balanced in any case to be safe) and no damage or abnormalities in rims or tires. He said it may be the AMG agility control suspension especially since I always drive it in the harshest Sport+ mode (although it still occurs in Comfort mode, but less so). Still doesn't make sense to me that they can't resolve such a vibration in this caliber of automobile. I've driven it for about a week since that service appointment and the vibration is still there although it varies - sometimes worse than other times and always between 100km/h-120km/h. I had mentioned before in a previous post that I was ok w/ it since it seems to go away after 15 mins or longer of highway driving, but now it is bothering me enough that I've set up another service appointment (Jan.7). I will post an update after that appointment. In the meantime if anyone has any further info on this issue and if anyone has info if this is a known issue that Mercedes has a technical bulletin on, please post. Thanks.

Good luck, keep us updated!

Have you had your wheel bearings checked? I had a similar scenario but different car brand, turns out it was a bad wheel bearing. Very similar sounding to what you described above

Thx for the suggestion - I will mention it to the service tech when I take it in.

Thx. I'll post update after my service appointment.

I would suggest check wheel bearing OR tire tread defect. Tires out of round aren't the only thing that can cause issue.... Have them swap a set from another vehicle and see if it's gone...

Thx, I'll mention tire tread defect to the service tech. Someone else also suggested wheel bearing.

Another clue?
It seems the vibration is way less or absent in warmer temps. This morning it was milder out (+7 degrees Celsius or about 45 Fahrenheit) & there was virtually no vibration at 100km/h to 120km/h. So that's another clue I will mention to the service technician. Not sure what it means.

Update: in the days leading up to my service appointment (scheduled for the 8th) the vibration was not present! So I decided to cancel the appointment and will re-schedule if it comes back. Very weird - not sure why it goes away then sometimes comes back. Right now its not there. Will monitor over the next few days.

Completely different car, 14 C300 4-matic m276, but I had a similar intermittent and temperature/duration speed dependent harmonic, that took MB about a month to find and fix. Car had 26k, and I put about 1k on their loaner.

I told them it was a howl/whine harmonic, that happened only when cold, and within a certain 15mph range. Cold temps made it worse, warm made it go away. Before taking it in, I recorded the noise and pinpointed the location as best I could, explaining that it felt like a bearing without oil, and that it was coming from the center of car, near the transmission, and only when cold or not warmed up. Also didn't happen as much when you were on the gas, more when you let off or coasted. All that lines up with what I've read so far.

Well, after a month of using high tech sonic and visual aides, and checking all combinations of tires/wheels/bearings on the corners, they tell me, driveshaft center bearing. Was a cheap fix under warranty. With a similar 4matic transmission, AWD setup in the C43, it might be worth checking out. I even told them I thought it was output bearing on front facing 4Matic shaft, and they still had it for a month, but I do credit them for eliminating the problem. Good luck all.

Hi all,
I have been following this thread for a few months now..

I got my C250 in January last year, instantly I heard the wining/howling and the vibration / metallic grinding in the steering wheel. This is constantly audible, but mostly at speeds between 90-120km. Frequency of the sound doesn't change if I increase/decrease speed. Best way to describe the sound/feel as a defect wheel bearing.

Went back to the dealer several times, they couldn't locate the problem. My car has been at the dealer for over 14 days..

They tried the following steps:

- Changed tires from Conti to Dunlop (19" AMG), non RFT but MO.
- Checked the crank shaft
- Wheels were balanced several times
- Changes front left and right wheel bearings
- Several other modifications

Changing summer to winter tires (17") resulted in less wining/vibrations/grinding, but it's still there.

Funny thing is that a few weeks ago, after 3 hours driving at the highway, everything was quiet... what a joy to drive. Unfortunately it's worse again..

So frustrating, thinking of selling my C..

Did you ever find a resolution? Found myself driving a family CLA this past weekend...when I got back in to my C43, I couldn't stop thinking about how terrible my ride quality is.

I've got a '17 E300 that I just bought CPO'd and it has a similar issue. Has been in five times, rear diff replaced, prop shaft balanced and angle adjusted, still vibrates around 73-75 MPH though pretty subtle. Found one other gentleman w/ similar symptoms; we've been chatting in this thread - https://mbworld.org/forums/e-class-w...ml#post7727234

Hi,
Brand new (2k km) 2019 C43, sedan, experiencing the exact same behaviour - strange high-freq vibrations, which are travelling thru whole car's body , and starting to appear at about 120km/h. They getting stronger (can even blur the rear mirror) and weaker during drive, without any noticable reason.
This is my 4th new car, never experienced such phenomenon before.
I have an dealer verification scheduled this monday, but I'm seriously doubt, if they will deal with it, except for standard actions like wheel rebalance etc.

I'll keep you informed.

BTW. My previous car (S4 B9) was brilliant, during 3 years of driving no single failure or claim. Smooth all the time, no cracking, buzzing, just perfect.

I wonder if the issue could be a combination of wheels and tires? Do those that have this problem have the 19" Wheels; and of course MB as far as I know now exclusively use Run Flats. it would be interesting to see if a set of the18" wheels and say a set of Non- RFT's like Michelin AS/3 would make a difference? keep in mind a 19" RFT will be so stiff that ever single little thing will be felt.. Even a non RFT in 19" is going to be harsh, especially with the overly stiff suspension on the AMG cars.

I was strongly considering a C43 in 2018..In the end although I was getting a great price I decided on an Audi A4 Premium Plus with all the goodies. I'd read just to much BS with these C43 cars. I also was not a fan of the staggered tire setup and RFT ( no other choice) My Audi with sport package has a square 18" setup and a real spare tire. Shame after looking at these forums, I don't think I'd ever consider a Benz. Shame cause they do look nice, and in the demos I've taken the cars were nice.

Squeaky wheels get the grease. There were 215,023 C-classes sold 2016-2018 in North America alone. I don't think we've breached a handful of with this issue, at least on these forums. For sake of arguing, let's assume there's been 10 cases of this? You're fooling yourself if you believe Audi doesn't have an issue that impacted <.005% of cars.

It must be a strictly Canadian issue, eh?
Too bleeding cold up there...

Guys if ur motor has grooved brake discs its likely the cause of thus humm vibration, I've switched numerous cars to grooved discs an they always have this humm or vibration afterwards ,,u can use yellow stuff pads they seem to solve it for most cars ,or another type of real good brake pads ,I've a C200 with recently upgrade groove brakes discs and its started to vibrate on highway ,took them off it stopped ,worth a shot ,,,

I had the same harmonic vibration detailed in various places. Car is a 2019 C43 Sedan with 19" AMG wheels and ContiSportContact5 SSR runflat tires. With my commute, I get on the freeway in like 5 minutes and quickly am up to 60-70mph cruising. I immediately noticed the "rolling" or "rhythmic" vibrations, almost like a regular pulsation that I could feel in the driver's seat, and then up through the steering column and steering wheel. It happened every day, and always shortly after getting up to cruising speed. It would always "pulse" with the same strength and intensity, as well as at the same rate (or timing). It would eventually go away after 5 miles or so, slowly decreasing in intensity until unnoticeable (but still at the same rate/interval). My car ended up having an extended stay after dropping it off for the first Service A @ 10,000 miles, which included addressing various other issues. After explaining in detail the issue, I was able to get the dealer to road force balance the wheels/tires as good will for the car being at the shop for so long. They diagnosed one wheel (front passenger I believe) with a slight bend, and fine tuned the balancing on all wheels. For the most part, this solved the issue of the vibrations, although sometimes I still get an infrequent similar vibration (albeit a "sloppier", more rumbling one) that occurs at the same time/point/speed when I hop on the freeway for my commute. However, the vibration dissipates MUCH quicker than before. I blame the issue on the soft 19" AMG wheels that can get bent easily (and I have been very careful with), and slightly unbalanced wheels/tires from the dealer/factory.

Same problem as you but never diagnose it. After I swap to winter rims, will need to check if there is same pulse.

Thanks for sharing your insight. Unfortunately, that pulsing vibration (for me at least) is not because of the bent rims.
I have stock 18 inch runflats and experience the same issue. Have the same issue with winter tires. The pulsing vibration happens the most frequently when speeds are above 95 km/hr
I am glad that fixing the rims fixed it for you though.
For my case, however, would be the driveshaft.
Edit: forgot to mention the winter tires are on different rims

additionally, i think the stiff suspensions adds to the car taking in the potholes/ bottoming out even more severely than a car with a softer suspension? anyone else thinks the same? of course in addition to the rock hard RFTS.