u/Ok_Guarantee5123

Hi,

I have a BMW Série 3 E91 318i (2012, 115k km, BMW N43).

I get a noise only when cold, between 1500–3000 rpm.

It sounds more like an air/vacuum noise (whooshing) than a metallic knock.

No warning lights, car runs fine, and the noise mostly disappears when warm.

Could this be a vacuum leak / intake issue / PCV?

Video attached.

Any ideas?

Thanks!