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?