[Boosted Autos]

Recently purchased an M235i second hand. On the way home I noticed an annoying rattle in the dash area that occurs between 1500 and 3000RPM consistently and relative to RPM, but ONLY when the Air Conditioning fan is running! Turn the fan off and the noise goes away entirely!

Curious to know if anyone else has had a similar issue and can point me in the right direction before I start pulling things apart.

It's definately inside the car (not the engine cover gutter plastic).

Thinking it may be a loose cabin filter.

Will report back if I find the cause.

[Paisano]

If this makes sense; does it occur on the left or the right side of your dashboard?

[Gilda G]

Same problem on my car (2015 m235). The dealer removed the glovebox and replaced the plastic fan. The new fan was quiet for about a month and the noise is back only when the fan is set to middle or high setting. Went back to the dealer they said its working properly... Which I don't get because its a loud humming noise. I've owned BMW's for 25 years and the AC fan was never this loud.. My fix I'm keeing the setting on low to avoid getting pissed off...

[Boosted Autos]

Originally Posted by Paisano

If this makes sense; does it occur on the left or the right side of your dashboard?

Sounds like the left side but towards the centre of the dash. My car is right hand drive.

[Boosted Autos]

Originally Posted by gildagjg

Same problem on my car (2015 m235). The dealer removed the glovebox and replaced the plastic fan. The new fan was quiet for about a month and the noise is back only when the fan is set to middle or high setting. Went back to the dealer they said its working properly... Which I don't get because its a loud humming noise. I've owned BMW's for 25 years and the AC fan was never this loud.. My fix I'm keeing the setting on low to avoid getting pissed off...

Intereting. my vibration only happens at cerytain RPMs and isn't reletive to fan speed at all. Adjusting the speed of the fan makes absolutely no difference. only change is that the rattle doesnt happen if the fan is completely off.

[BMWZ4]

Originally Posted by Boosted Autos

Intereting. my vibration only happens at cerytain RPMs and isn't reletive to fan speed at all. Adjusting the speed of the fan makes absolutely no difference. only change is that the rattle doesnt happen if the fan is completely off.

My wife's 2014 328 had this as well. It was the fan and motor in the passenger foot well area. They replaced the entire unit and she hasn't heard the vibration or noise since.

[Paisano]

Originally Posted by BMWZ4

My wife's 2014 328 had this as well. It was the fan and motor in the passenger foot well area. They replaced the entire unit and she hasn't heard the vibration or noise since.

This.

However, I only heard of these failures happening in colder climates.