[phabmasta]

Hi all,
Recently got into a '17 320i with manual trans. I have just noticed a humming noise above 70 MPH, which seems to go away if I put the car in neutral and coast for a few seconds. It oscillates if I keep car steady at 75 MPH, but seems to go away over 80 MPH. It is not very loud (only hear it windows up, audio off), and can't really feel it when I hold shifter. Rotated tires, checked pressure, just to rule out. Just wanna know if it could be serious enough to take in somewhere, I can live with the noise... or just keep over 80 the whole time

[Orion4]

Does the "humming" sounds like it goes up in frequency as you go from 70 to 80 or sould the same?

[phabmasta]

The frequency does not seem to change, sound just gets more noticeable at those speeds.

[ooshnoo]

I'm on my second set of wheels and tires, and I got the same thing happening since I got car. Get it checked for play in the driveshaft splines.

[phabmasta]

Ran in to this old post in the E90 forums, pointing to rear diff as the problem.

https://www.e90post.com/forums/showp...26&postcount=6

Gonna take car back to Carmax where I got it see if they'll do anything about it, it is still under their 90-day warranty.

[Solidjake]

Differential/driveshaft. A lot of members have this issue including me.