[mjdth]

I’m pretty sure this is just a defect but whenever I hit the max defrost button and it gets up to speed (after a couple of seconds) there’s a quite loud constant humming noise. Almost like someone blowing air over a beer bottle to make that whistling noise. Never heard anything like it before from a car, is anyone else getting this?

[kozzi]

Originally Posted by mjdth

I’m pretty sure this is just a defect but whenever I hit the max defrost button and it gets up to speed (after a couple of seconds) there’s a quite loud constant humming noise. Almost like someone blowing air over a beer bottle to make that whistling noise. Never heard anything like it before from a car, is anyone else getting this?

Yes, I think I have this issue. Occurred to me on a very cold day at start-up and without letting the engine warm up at all to driving at highway speeds within minutes. Can't recall if it was humming before highway speed but for sure at. Haven't had a chance to replicate it but now I will try. It is definitely NOT wind / road noise liked stated in other threads. Next chance I get, I will try and replicate but it may not happen due to the weather warming up.

[mjdth]

Yeah it happens every time for me. Also happened when the car was warmed up.

Bringing it in tomorrow for a few things anyway so I guess I’ll add this to the list...

[kcleuk]

Originally Posted by mjdth

Yeah it happens every time for me. Also happened when the car was warmed up.

Bringing it in tomorrow for a few things anyway so I guess I’ll add this to the list...

Any update? I have the same

[KTMF]

Originally Posted by kcleuk

Any update? I have the same

Don't know if there is a fix, but it is a known issue (to BMW)

NHTSA ID Number: 10145304

Manufacturer Communication Number: B640518

Summary

EXCESS NOISE WHEN DEFROST BLOWER IS AT MAX: Loud, rushing, wind noise is heard from ventilation outlets, as shown in video, https://************/V640418 when defroster blower is set at maximum speed.
Vehicles
MAKE MODEL YEAR

BMW X3 2018
BMW X4 2018

[kcleuk]

Originally Posted by KTMF

Don't know if there is a fix, but it is a known issue (to BMW)

NHTSA ID Number: 10145304

Manufacturer Communication Number: B640518

Summary

EXCESS NOISE WHEN DEFROST BLOWER IS AT MAX: Loud, rushing, wind noise is heard from ventilation outlets, as shown in video, https://************/V640418 when defroster blower is set at maximum speed.
Vehicles
MAKE MODEL YEAR

BMW X3 2018
BMW X4 2018

So BMw will not fix or address anything? It becomes a "it is what it is"?

[KTMF]

Originally Posted by kcleuk

So BMw will not fix or address anything? It becomes a "it is what it is"?

No I didn't say that. Since BMW is aware of the issue, you can likely provide the the Bulletin number and they can look up the procedure to diagnose, and hopefully repair. good luck.

[mjdth]

I brought it in a while ago and they replaced the blower motor. Haven't noticed the humming as much but I also haven't tested it in a while with the max defrost on.

[Neo1130]

Normally there are some foam seals on the diverting flaps, those will start to vibrate with the air blowing over them and cause a hum type noise.

[sinbad4]

I had similar issue.. ended up being many months long process.

https://x3.xbimmers.com/forums/showthread.php?t=1496114

[mjdth]

Yeah just used the defroster again today. Even though the blower motor got replaced it still makes a loud howling noise on max defrost. Yay.