HELP Pls - Groaning noise coming from Ventilation system

[M4 Newbie]

Hi Guys,
I have a 2018 F82 Competition Pack M4 I've owned for the last 3yrs (since 4k miles) and whilst I love the car, unfortunately I can only drive it with either the climate off, windows open or the stereo up loud, or any combination of the three .

It has a seriously annoying noise that is activated by turning on the climate fan. The car has been in three times to two different dealers for it and every time it has come back just the same.

1. The noise does not increase with Fan speed
2. The sound seems to emanate from somewhere reasonably central behind the climate controls towards the engine
3. It makes no difference if the AC is on or off
4. I don't believe it to be the active sound as its not coming from the speakers.
5. It can't be heard under the bonnet, maybe due to the engine noise being louder.
6. Apparently they have checked to ensure there are no leaves caught up in the fan (a historic issue with other BMW's)

And no its not me, during one of the visits to the dealer when they were looking at me like I was a mad man, I challenged them to find me another car that made the same noise and they fired up another F82 in the showroom, which of course made no similar noises. Despite this two workshops have not been able to fix it.

Please listen for yourself and let me know what you think (its particularly prominent around 40 secs in).

https://youtu.be/n4tn-NsjZ1c

[mapster37]

see if the noise changes by cycling the a/c button. not the fan speed control

[M4 Newbie]

Thanks mapster37
It makes no difference if the AC is on or off.

[AutoTalent]

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