N52B30 Whining noise at high RPM

[thevihiman]

E82 2010 128i, N52B30, 6MT, 106k miles

I've had a whining noise i'm trying to track down. Its been there since ive had the car (78k miles), but has become very noticeable ever since I mic'ed up my engine bay to record. It is proportional to RPM, not noticeable at idle. It also seems to lag a bit picking back up when revs drop between shifts

Video:

View post on imgur.com

Is this noise normal in the N52 or indicative of something on its way out?

I suspect alternator or power steering pump, but I'm trying to triangulate before dropping a bunch of money on parts. Will eventually have to replace all my drive belt components but want to prioritize where this noise is coming from. Anyone have any advice?

[mkeiser]

video isn't working but you can isolate drive belt components by removing the belt and running the engine to see if the noise goes away.

[thevihiman]

wouldn't removing the serpentine just isolate whether or not the sound is coming from the drive belt components, not triangulate which one in particular?

let me try a different video platform, hopefully this works: vimeo.com/1183192676?fl=pl&fe=sh

[mkeiser]

Originally Posted by thevihiman

wouldn't removing the serpentine just isolate whether or not the sound is coming from the drive belt components, not triangulate which one in particular?

let me try a different video platform, hopefully this works: vimeo.com/1183192676?fl=pl&fe=sh

Yes. Takes a minute to verify if its drive belt components or not. Mechanic stethoscope on the pulley bearings to check em out.