S50 whining noise under acceleration

[m3f_bmwstephen_a41ab40f37]

Hi all-


Have this high pitch whining noise whenever the car is under acceleration. Can anyone identify where this is coming from?


Video link below:


https://vimeo.com/173779658

[m3f_B329iC_60375c0671]

Reminds me of a power steering whine when fluid is low or air is in the system.

[m3f_bmwstephen_a41ab40f37]

Hmm ill check the system. Also ill note that the whine occurs when the car is in park or neutral and the the throttle is open

[m3f_M3n00b_e01f72a830]

Any whining under acceleration usually comes from my wife

[m3f_bmwstephen_a41ab40f37]

Any whining under acceleration usually comes from my wife



quoted for the books:hattip:

[m3f_M3n00b_e01f72a830]

quoted for the books:hattip:



:beer:

[m3f_98M3csm_04d446cd70]

Any whining under acceleration usually comes from my wife



Ha. Well said.

[m3f_Evtron_da8d65bde7]

Any whining under acceleration usually comes from my wife



Flawless.

[m3f_kyrix1st_9c2b4efe25]

I'll try to be constructive and guess that it is related to the driveshaft since it only seems to happen under the acceleration. It could be that your drivetrain is making contact with exhaust part due to loose support bearing; it could also be related to clutch/flywheel. I've only heard such sounds when wheel bearing went wrong, so it could be your rear as well (but wouldn't wheel bearing "always" make sound when wheels spin? )

[m3f_kyrix1st_9c2b4efe25]

I'll try to be constructive and guess that it is related to the driveshaft since it only seems to happen under the acceleration. It could be that your drivetrain is making contact with exhaust part due to loose support bearing; it could also be related to clutch/flywheel. I've only heard such sounds when wheel bearing went wrong, so it could be your rear as well (but wouldn't wheel bearing "always" make sound when wheels spin? )



Sorry did not see that it happens in neutral. Then I think it is almost definitely engine related (maybe belts?).

[m3f_B329iC_60375c0671]

If the noise changes up or down with RPM then I would suspect a belt, tensioner or a pump,water/steering or alternator. Easiest way to determine belt or pump in remove one belt at a time and run the engine. If it's the alternator bearings you can rotate the alternator by hand and feel the bearings to see if they are binding or if the brushes are worn out.