Engine whine

[WadeM]

My wife's M3 has been in for service 4 times for a engine whine. They have replaced belts and pulleys, but the noise just comes back.
Anybody else have this issue.

[ntg44]

Didn't have it myself, but any chance it's the alternator? Not sure what else would make a whine besides that. Does the pitch of the whine change with the revs, or is it a constant pitch?

[WadeM]

Originally Posted by ntgarage44

Didn't have it myself, but any chance it's the alternator? Not sure what else would make a whine besides that. Does the pitch of the whine change with the revs, or is it a constant pitch?

Yes, it will change when it revs. It's the worst on cold starts. We are supposed to get the car back today with a new belt.

[ntg44]

Not sure if the belt would be the problem then. A slipping belt makes a horrible squealing sound, there's no mistaking it. The only thing I have experienced in the past making a sound like you describe is the alternator, but either way, hope it gets sorted out. Best of luck.

[Lee808]

Or it's possible your hearing the transmission?

[zillymc]

I have something similar to this - I had them look at it 1200 mile service and didn't see any issues, but the tech heard it as well. I haven't noticed any issues with the car, and I had a MY16 M4 so I have something to compare it to - and it for sure has a wine comparably. It's worse at like 3-4k. I just try to ignore it lol, might just be transmission noise who knows.

[WadeM]

Originally Posted by zillymc

I have something similar to this - I had them look at it 1200 mile service and didn't see any issues, but the tech heard it as well. I haven't noticed any issues with the car, and I had a MY16 M4 so I have something to compare it to - and it for sure has a wine comparably. It's worse at like 3-4k. I just try to ignore it lol, might just be transmission noise who knows.

Dealership changed a belt (again) and the noise is gone. As I mentioned it's been in 4 times with the first being the 1200 mile inspection, changed a belt previously. I currently drive a M4 and have never heard the noise, had M4 before this one and never had a noise. Hopefully we don't have to go back again, if we do I'm asking for them to take the car back.