Whining noise 2017 C43 Sedan comprehensive guide really useful. Read Here

 

Well, completely unrelated to the topic.

 

Adding to this I have a 2017 E43 and have been battling this issue for a year, we have bad dealers in Ottawa Canada. Luckily I have an extended warranty but it’s coming up.

The dealer replaced the diff last week and the noise still is there.

rear diff part # 213-350-07-01

Dealer notes:
CONFIRMED CUSTOMER COMPLAINT, PERFORMED ROAD-TEST FOUND NOISE PRESENT ON SMOOTH ROADS ON DECELERATION NOT TIRE NOISE OR WHEEL BEARING NOISE SUSPECT REAR DIFF, LIFTED VEHICLE PUT VEHICLE IN DYNO-MODE, HAD VEHICLE SPUN TO 100KM/HR CHECKED HANGAR BEARING AT DRIVE SHAFT VERY SLIGHT NOISE, CHECKED REAR WHEEL BEARINGS NO NOISES, CHECKED REAR DIFF FOUND REAR DIFF MAKING LOUD HOWLING NOISE. SUSPECT NOISE IS TRAVELING TO HANGER BEARING.

 

Thanks for chiming in, frustrating to hear the E 43 is also affected by this defect, sorry to hear that you have to deal with it, is your replacement a remanufactured part too?

 

According to the part # it says remanufactured in the online description.

 

Keep pushing your dealership, they can't throw the "cannot duplicate" card that they like to throw as both you and the shop foreman can hear it, from what I learned reading this thread, there are rear differentials out there that doesn't whine.

 

@GWSHARK Sorry to ping you buddy hope you don't find me annoying but I sent you a PM on the update of my car if you have a minute please read and reply but if you don't, don't worry about it until you have time.

In short: for those that come to this thread for the very last time, the whining rear differential issue on my 2017 C 43 after the replacement a few days ago (again...) remains unresolved unfortunately,

Outside temperature at 10 degrees celsius or below, whining often happens when doing light throttle if you open the Vehicle Data screen under DYNAMIC SELECT, if you hold the throttle in between 10%-20% at around 78-84 KM/HR (or 48-52 MILES/HR) is the loudest if you are not going downhill.

Under those conditions, you might hear it if your rear differential has this noise, the noise may be found on all C/A/S/W205 C 43 so 2017-2021 C 43, the noise is also the loudest when you just started the vehicle in the morning and driving at those speeds, so basically loudest when the rear differential isn't heated up yet. It is probably a characteristic of the vehicle and don't worry as your rear differential is not actually broken, it is really just an annoyance...

For those that keep seeing this thread and find it annoying because I keep on replying to it, I am sorry and this is most likely the last time I am going to go in for service to try to get this whining issue resolved.

@osmanbenz I am hoping your experience is better, best of luck to you and others that are trying to get this resolved. Me on the other hand I think I have given up.

 

My saga continues. Dealer replaced the rear diff. Sound has been worse. Mine sounds like a wheel bearing at 70-80Kmph Now the dealer says it’s the front diff and are replacing it this week under warranty. I foresee that won’t fix the issue either.

 

Ugh not only did the sound didn't disappear, it sounds worse???
They checked the fluid level of the differential and it is correct right? What about the condition of the fluid?

 

I am not sure if it’s from all the parts being taken off and on, they claim the diff fluid is at the correct level. The sound may sound worse as I removed my winter tires. The car was a supposed to be ready Friday but I haven’t heard anything. I foresee they changed the front and still hear the noise.

 

Best of luck that it is actually solved when you pick up the vehicle on Friday

 

@W205C43PFL Tried to PM you, Sorry I really don’t have much more to add. The issue is no longer present in my car, they did replace it and 3rd one seems to be ok. I no longer have the whining noise when I lift off gas at around 80-90km/h. I don’t have or know where the paperwork is. Sorry wish I could be more help, and I know how annoying these things can be when you’re listening for them.

 

@GWSHARK Thanks for your reply, yes I am glad yours is fixed and remain fixed so you can properly enjoy your car.

Me on the other hand, strangely the whining noise for me only happens when under light throttle because for example if coasting, sound is gone and if throttle input (as shown on the Vehicle Data screen under dynamic select is more than 20% then the noise also disappears even at those speeds 78-84 km/hr.

Don't worry about the paperwork, since it has been a while thanks again for all the assistance you provided for other forum members and me as well. Strange the PM isn't working for you though, I think you should bring it to the attention of forum staff just in case if others send you a PM you aren't able to reply as well.

Thanks again!

 

Just to confirm you said the 3rd one did it, you mean it is the 3rd differential in total (so factory + 2 replacements) or you mean factory + 3 replacements?

 

@GWSHARK This will be tremendous help if you can please PM me your phone number and/or name and/or VIN number whatever you feel the most comfortable sharing and/or when did you take the vehicle in for this issue if you can remember the date. My service advisior called me today to have it looked at by shop foreman after it being replaced last week and I told them it still whines, they need more information. This is the dealership you recommended me but he talked to your service advisor and he don't remember a thing. All help is appreciated!

 

@GWSHARK Good morning! Thanks again for you offering to help I really really appreciate it a lot! I have PMed you my phone number, hopefully that helps you reach me easier, please text me when you have a minute thanks again!

 

An update, my dealership pulled the "It is normal" card as expected, guess consumers lost again.

 

I would push back again, I picked up my car Friday and of course the noise is still very much there. They have now replaced rear diff, driveshaft, front diff and for some reason rad fans. The foreman is at a loss. I told him it’s the rear diff still. They believe it’s not possible since they replaced it. It goes back again Monday. We are now at 5 weeks of the car being at the dealership.

 

Very happy to have found this thread as I’m experiencing something similar. I don’t have a C43 or E43 but I have a 2020 C300. What I’m experiencing is like a whirling or booming noise at high speed. Mine happens with the throttle pressed and while coasting, however it happens at about 90+ mph, getting increasingly worse with speed. I first noticed it about two years ago but it wasn’t bad and I didn’t think much of it as I don’t normally drive those speeds. However I’ve been noticing it more, and on a recent ski trip where I had a seat folded down, it was VERY noticeable. It’s definitely coming the rear/ trunk area and seems to resonate inside of the trunk, so with the seat folded down the noise was very strong. I believe it to be the diff because this is not the first time I had this happen. On a 2010 C300 I owned many years back, I got rear ended in traffic and the push from it made a grinding noise from the rear. Next thing I knew it was making the same sound I’m experiencing now but much worse and the diff had to be replaced after the accident. My 2020 C300 was rear ended pretty badly at a red light two weeks into ownership so based off past experience I believe that in the accident it messed up my diff. The problem is, I can’t just bring it in and say my car makes a weird noise from what I think to be the diff at 90+ mph as they won’t even try to replicate that, so I feel pretty out of luck. I’m thinking of maybe bringing it in as it seems to be getting worse, but I won’t be surprised if they give me the run around. To me it’s either got to be the diff or a wheel bearing. It’s had two different sets of tires so it’s not that. I don’t feel a vibration in the front but I’m thinking of putting someone in the backseat and getting to speed to see if they feel a vibration.

 

My dealership just says it is normal because apparently they have a C 43 that does the exact thing at exact speeds and mothership also replied back say it is normal ugh.

 

Sorry to hear about the rear ending but glad you came out unscathed, I would try a different dealership if yours is not even interested in replicating the issue or at least going for a "hear this" drive with you.

 

I want to push them but the dealership just simply ignore me since mothership replied back it is normal, super frustrating I also need forum member GWSHARK to reply as well as he got his car fixed at this same dealership a few years ago and the sound didn't reoccur but I haven't got a reply, I understand that I might be bothering forum member GWSHARK too much though.

 

Forum member osmanbenz, I have a thought, see if your dealership is willing to help you order a new (not reman) rear differential and one straight from Germany, if they are just installing the ones that are available in Canada already, chances are, those are part of the bad batch. The fact remains, if something was broken on the assembly line, that creates a bad batch. Just for example a domino effect if something is programmed improperly on the assembly line, every product that gets produced will be flawed, ie. Bad batch.

 

Yeah I’m feeling like I’ll just make the advisor or foreman get in the back seat and get the thing up to speed. It happens every time I get up to those speeds so it’s not a come and go issue.

 

Yup but meanwhile, to sum up:
Forum member stockbmw had his rear diff replaced once and the noise is gone and has not reoccurred, the repair was done back in 2019.

Forum member GWSHARK had his rear differential replaced a couple of times (not sure if replaced 3 times or 4 times), noise is finally gone, the repair was made when the car had around 50K KMs I think I read and now he has around 110K KMs, no recurrence at all.

Me on the other hand have the rear differential replaced twice at MB Markham, same dealership as forum member GWSHARK that he recommended me in this thread, but noise is still there and unlike how MB Markham helped forum member GWSHARK, they simply pulled the "it is normal" card at me and no longer willing to work with me, they even claim that they have a C 43 with them that makes this noise hence why they say it is normal.

Any suggestions are truly welcome.