u/Christian_GM

Hi everyone, my E39, when accelerating, makes a very loud air intake noise, like a huge truck accelerating — a very, very loud sound, as if it’s taking in twice as much air as it should.

In the video, you can clearly see what I’m talking about. After a few revs, the noise changes — that loud air intake sound goes away. (Ignore all the errors on the dashboard; I did an automatic-to-manual swap and haven’t coded it yet, this intake noise issue was already happening when the car was completely stock.)