Posts: 3
Joined: Thu Mar 31, 2022 9:12 pm

Re: High whistling sound

Sun Apr 17, 2022 8:27 pm

@HarrisonB, is the noise the same as the noise that @AnasAwad filmed in the video?

Posts: 4
Joined: Sat Apr 16, 2022 8:57 am

Re: High whistling sound

Sun Apr 17, 2022 9:34 pm

No I don’t think so. That was a short clip. Mine raises in pitch as I accelerate and lowers as I decel. The noise is definitely associated with the motor.

Posts: 3
Joined: Thu Mar 31, 2022 9:12 pm

Re: High whistling sound

Mon Jun 20, 2022 11:12 am

Thanks all! Today I get delivery of a 2017 B-Class that we are buying from Carvana!! Hopefully we don't have any issues.

Posts: 9
Joined: Sat Dec 08, 2018 10:50 am

Re: High whistling sound

Sun Aug 28, 2022 10:07 am

Through lots of research, I have found that that sound means you have an issue with the bearings in the motor. the mercedes dealer said I needed a new motor. I contacted QCCharge in Vista, Ca. and I'm going to replace the bearings and re-build the motor for $4,500. To me it's worth it. I have 50,000+ miles on mine and I think it's a great car.

Posts: 2
Joined: Sun Oct 16, 2022 2:12 am

Re: High whistling sound

Sun Oct 16, 2022 2:24 am


So we've had this sound since the first year of owning the car. Our stand has only diagnosed it now as a Drive Unit failure.

Is there a chance we can fight back that they didn't do anything while the car was under warranty? They want us to replace the whole motor.

The car has had a chance of engine failure for years and only now did they say anything. It's a widely known problem with the B250e, and very easy to diagnose, so I'm surprised they failed to diagnose it over all this time.

Our noise is getting a little worse over the years, but it has always been bad. It's definitely been there since the first year. Many Tesla models also have this problem, and they often start failing at 10k–20k miles. Ours is already at 90k.
Tesla replaced a lot of drive units due to this "milling sound" problem, caused by a bad bearing. It even increased the warranty of all cars retroactively from 125k miles, 8 years to unlimited miles, 8 years. But Mercedes isn't doing much.

What do you suggest me to do?


Return to “B-Class Electric Drive News”