[trilax59]

Sorry to dig up an old thread here. I have a 2016 M235i RWD ZF8 auto with 273xx miles on it. I picked up the car CPO in August of 2019. Since I bought the car, I noticed there was a whine sound in 2nd gear that came on at 2600RPM and gradually got louder until about 3100RPM. This whine is evident in every engine driving mode, automatic transmission mode, sport automatic mode, and manual mode. I haven't had time until recently to bring it to the dealership. I dropped it off at the dealership on December 23rd and got a call this morning (January 9th) that the car was ready. They informed me that they had replaced the entire transmission under warranty.

I pick up the car, deal with the paper work, and drive home. On my way home, I drove the car like a baby to not put any stress on the new transmission and to let it break in. However, right before I got home, I decided to replicate the previous issue to see if it was fixed. To my surprise, the whine sound was still there in 2nd gear at the same RPM range. I immediately drove it back to the dealer and went on a drive with one of the techs (shop foreman was out today). We went on a quiet road and went through all the gears. We heard the whine sound in 2nd gear, as expected, and also heard the same sound ever so slightly at 2950-3050RPM in 4th gear. The sound was not evident in any of the other gears.

They are taking my car in and going to run more tests to determine the cause of the sound. I am absolutely dumbfounded what the issue could possibly be, considering the sound is gear specific. I would think a possible turbo or differential issue, but the sound is not present in any other gears or at other RPMs from previously stated. I doubt it's a transmission issue because they just replaced it, unless they lied that they replaced it and never actually did...

The car is under warranty so BMW will take of everything. However, does anybody have any idea what the issue could possibly be?

Appreciate any input or advice in advance!

-Ryan