Strange Static/leaking noise when above 1.5k RPM?

[Robert2137]

Hey guys, I've been following this Forum for quiet a while and decided to finally make an account considering I didn't seem to find a problem like this.

I am the owner of a lovely 2012 (pre LCI) 116d BMW F20. Car has about 164k Km on it (about 102k miles) and for some reason, out of nowhere a strange noise showed up today.
I didn't have my car for 5 weeks, because I recieved a new ECU cuz BMW fried it. 
As I finally went for a spin with the car, I started hearing this weird Static/Leaking/grinding(?) noise above 1.5k RPM all the way up to 4.5k RPM.
While in Idle/changing gears it seems to not make the noise. 
It doesnt matter if i am standing or actually driving the car, the noise is still there. 
Funny enough even if I rev it up all the way to 4k rpm and let it slowly drop back down to X RPM the noise is still there. 
Oil changes have been done regularly. Last oil change was about 3k km ago (2k miles). 

Do you guys have any idea what the problem would be?
Thank you guys in advance.

Cheers!

[Greydog]

Morning Robert

Welcome to the Forum

Noises are sometimes a pain to track down, so to start some questions (1) Manual or Auto ? (2) Does it get louder with increased revs ?

I would start with the belts and pulleys at around a 100k they will need checking/changing anyway, so first a visual inspection of the belt is it in decent condition. Next, pulleys put a squirt of WD40 into the centre of the pulley where the bearing is. Do not drown it or get any on the belt. If the issue is with a failing pulley (often the tensioners) when the offender is lubricated the noise will quieten or disappear. If it is a pulley I would change belt and the offending item

Have the Brakes been checked ? it could be a sticking pad rubbing 

Good luck tracking it down 

Dave