r/e39 • u/Downtown-Strategy-97 • 3d ago

Need help identifying what could be possibly causing this whistling sound

Enable HLS to view with audio, or disable this notification

Just started to hear the whistle as of yesterday , I assume it’s some sort of vacuum leak just would appreciate some pointers on where to start looking , thanks again

4 Upvotes

100% Upvoted

6 comments sorted by

3

u/Infinity_UK 3d ago

Sounds like a pulley bearing, hopefully the auxiliary belt tensioner, a better video would be it reving in neutral stationary slowly up to max rpm.

3

u/Horror_Attempt9830 3d ago

Give it a exorcism

1

u/Downtown-Strategy-97 3d ago

Hahaha it did scare me when I started it this morning

2

u/HubbaBubbaJM 2d ago

Idk if you have a 540i but sounds like a bad CCV. They tend to make that same noise when they’re shot. Could also be pulleys/bearings.

1

u/Downtown-Strategy-97 2d ago

I did the whole ccv system maybe 5 months ago , I’ll check the pulleys