Air Noise from heater fan.
 

I am a bit of an :whew::whew:

When I put the fan on 3 stripes, I hear the noise from the air coming out of the center outlets. Thats bugging me a bit.
I have had quite a bit BMW’s (old and newer models) but never heard it, on low fan speeds.

Who had an idee what I can do about it?, other than not using the outlet.

It’s not noise from a bad blower, I know how that sounds like.

Record the sound. I have had chirping at certain fan speed and since I run on auto it decides the fan speed (but wish displays it).

I'll just change the tempo up or down to get a speed without the chip.

It's definitely from the motor in my case maybe enough dirt on the squirrel cage to upset balance only a problem when it finds a harmonic.