High pitch howl from A/C vents

[hyde]

I noticed today (driving without the radio) that heating system has a strange whistling howl type of noise even with Auto at lowest setting.
I do not hear this if I change it to manual and lower the fan all the way down.

Does anyone else have this issue? The annoying thing is that it is not a consistent howl, it's varies in pitch up and down, and not in a regular fashion, and not directly linked to engine rmp either.

[wjbender]

Not present with my HVAC system

[NPickles]

Do you have any/many of the vents closed?

I have heard this where a couple of vents are closed and the back pressure means the air finds the tiniest gaps to escape through.

[hyde]

Originally Posted by NPickles

Do you have any/many of the vents closed?

I have heard this where a couple of vents are closed and the back pressure means the air finds the tiniest gaps to escape through.

Will check this out on the way back home tomorrow. Thanks.

[oshiri]

had a similar problem. i described it more as a 'whistling' noise, but i thought it came from the window or door seals. it happened particularly near the driver's side (on the right side in Australia) and particularly when driving at higher speeds. It only happened to me once when I was driving to the ski (around 2 degrees celsius outside). hasn't happened again since. could never figure it out but it did bug me to no end during that drive. keen to hear if you figure out what it is!

[5tony]

Mine sometimes makes a whistling sound, but I can make the noise decrease in intensity by adjusting the upper vent temperatures with the red/blue thumbwheel.

[BMW06]

Originally Posted by hyde

I noticed today (driving without the radio) that heating system has a strange whistling howl type of noise even with Auto at lowest setting.
I do not hear this if I change it to manual and lower the fan all the way down.

Does anyone else have this issue? The annoying thing is that it is not a consistent howl, it's varies in pitch up and down, and not in a regular fashion, and not directly linked to engine rmp either.

Have exact same issue with my 2015 35i. I usually keep system on auto and the fans on lowest level. It has been 3+ weeks and 1K miles now. This week, it seems to be improving and noise is comparatively infrequent (I think). I am going to monitor it for another week before making my service appointment.
I mentioned it to my sales guy 2 days after delivery and he recommended to set up a service appointment.
Hoping that these are new parts setting in.

[quattrospeed]

Funny I have EXACT issue with my '12 335i

[retx]

I thought this was caused by the valves insides the vents when the air pressure is unevenly drew.

[hyde]

Originally Posted by BMW06

Have exact same issue with my 2015 35i. I usually keep system on auto and the fans on lowest level. It has been 3+ weeks and 1K miles now. This week, it seems to be improving and noise is comparatively infrequent (I think). I am going to monitor it for another week before making my service appointment.
I mentioned it to my sales guy 2 days after delivery and he recommended to set up a service appointment.
Hoping that these are new parts setting in.

Keep us posted if you ever take it in service and what they have to say, if they do anything?

Originally Posted by quattrospeed

Funny I have EXACT issue with my '12 335i

Did you try anything to fix it or reduce it? I guess it's not as bad if you have the stereo on, but it's just a bit annoying.

To update my situation, I opened all vents and made sure all vents in the back were open too, I can still hear it, and it's inconsistent. It's as if there is something blocking the flow of air and the compressor is trying to compensate it by randomly adjusting the blower in micro adjustments.

Do you all have 4-Zone climate control or is this present with 2/3 Zone climate controls too? I am thinking of trying to keep the rear off through iDrive to see if that helps. I usually keep it in Sync people like to play with temp in the back.