[halcyon_waves]

Hi y'all,

I've done a fair amount of research and can't seem to find anyone with a similar issue. I currently drive a 2013 F30 335i 6MT and once in a while at very low speeds it'll produce a resonating sound similar to a train or large bus coming to a halt, or if you were to run your wet finger around the rim of a wine glass continuously. Here is a video of the sound:

It only happens below 10 mph at low rpm, once it's past that it goes away. It also happens both when I accelerate and when I come to a halt (more so the former). I've also put the car in neutral and let it roll on it's own, and the sound once again occurs. I would say that this happens about 10-20% of the time while I'm driving, so when I took it to my mechanic I wasn't able to reproduce it and therefore wasn't able to diagnose. But once it happens, it usually keeps going until I end the trip.

Any ideas what this could be? Perhaps old/worn out parts? My car only has 48k miles.

Thanks in advance!

[Sea-Tac]

This may sound funny, but check your power steering fluid if it is low, top it off. Had a similar issue in a 2014 f30. howling at low speeds. I just happened to notice the PS fluid was pretty low so I just refilled it...no more howl.

[halcyon_waves]

Originally Posted by Sea-Tac

This may sound funny, but check your power steering fluid if it is low, top it off. Had a similar issue in a 2014 f30. howling at low speeds. I just happened to notice the PS fluid was pretty low so I just refilled it...no more howl.

I thought it's electric? I don't see what would look like the normal power steering fluid cap.

[upsidedownfunnel]

Originally Posted by Sea-Tac

This may sound funny, but check your power steering fluid if it is low, top it off. Had a similar issue in a 2014 f30. howling at low speeds. I just happened to notice the PS fluid was pretty low so I just refilled it...no more howl.

Uh, I'll give you that this problem was common in previous BMWs that had hydraulic steering. However, all F30s use electric power steering. There is no power steering reservoir. Are you sure you're not mistaking it for an old car? perhaps your E90 335i?

Originally Posted by tarheelsauce

Hi y'all,

I've done a fair amount of research and can't seem to find anyone with a similar issue. I currently drive a 2013 F30 335i 6MT and once in a while at very low speeds it'll produce a resonating sound similar to a train or large bus coming to a halt, or if you were to run your wet finger around the rim of a wine glass continuously. Here is a video of the sound:
...

Any ideas what this could be? Perhaps old/worn out parts? My car only has 48k miles.

Thanks in advance!

It could be a lot of things. It could be your alternator or some accessory pulley making that noise. Next time it happens, pop the hood and try to pinpoint the noise.

[zeikei]

I vote for brakes. Any disc getting hotter than others?

[RoundelM3]

Yeah...does sound more like brakes. Maybe time for new pads/rotors?

[halcyon_waves]

Originally Posted by zeikei

I vote for brakes. Any disc getting hotter than others?

I'm not sure? And the noise doesn't happen when I'm braking.

[halcyon_waves]

Originally Posted by roundel335

Yeah...does sound more like brakes. Maybe time for new pads/rotors?

Last I checked they were fine, but I'll give it another inspection when I bring it into the shop again. I actually did suspect brakes when I first heard the noise but it usually happens when I'm not applying the brakes. Maybe the wear indicator, but it shouldn't sound like that at all.

[halcyon_waves]

Update: I had new brakes installed and rotors resurfaced and the issue went away. I just couldn't believe how loud the noise was for it to be a brake issue!