[MagnusT]

If it's cold damp weather and I park the car ten minuters or half an hour, when I get back and start the car all windows are immediately, in a few seconds, totally fogged up. I have to sit and wait between a minute or two before I can see out at all again.

All my previous cars have fogged up if my jacket has been very wet or snowy. But this is something different, I can come back to the car from indoors, very dry and this still happens. Another difference is that in the M2 it fogs up the second the fan starts. I don't recognise this from other cars where it has at least taken a handfull of seconds more before fogging up.

BMW has checked the car but all electronics and mechanicals in the ventilation system reports back with no errors.

I'm not sure what I should do next.

[Artemis]

Originally Posted by MagnusT

I'm not sure what I should do next.

Stop making whoopee inside your car.

[MagnusT]

Or do more and not see it as a problem? Hahaha.

[Dr.Deep]

I think everything is fine. Noticed that from time to time. One you start the car, you get some left-over warm air into the car, what result in foggin up because of the difference from the air in the pipes and air in the car itself.
May come because the car closes down the air vent holes so the air can’t get out. You notice that if you turn off the car copletely and keep siting in it for a while. After some minutes you will hear some noise, hard to explain, like if you put a CD or take it out of a CD player, just longer.

[AndrewC1989]

Actual Solution:

When you get in the car, set your desired temp on the thermostat and then press the auto button on the ac/heat unit. You'll see the ac light come on. It will blow a/c out of the 2 innermost vents for a little in order to dehumidify the car. The outer two most vents will blow heat so you don't freeze to death. Just make sure the middle red/blue knob in between and below the two inner vents is set to blue.

[MagnusT]

Strange, I always have AC on auto? Not 100% sure what the middle vents adjustment is set to, I think somewhere in the middle between red and blue. The air coming from those vents are not the culprits though.

Any additional idea?

[MagnusT]

Originally Posted by Daaan

I think everything is fine. Noticed that from time to time. One you start the car, you get some left-over warm air into the car, what result in foggin up because of the difference from the air in the pipes and air in the car itself.
May come because the car closes down the air vent holes so the air can’t get out. You notice that if you turn off the car copletely and keep siting in it for a while. After some minutes you will hear some noise, hard to explain, like if you put a CD or take it out of a CD player, just longer.

I know the sound. There might be a PUMA on that post park function, I'll check.

[AndrewC1989]

Originally Posted by MagnusT

Any additional idea?

Make sure the recirc is off and crack a window.

[Artemis]

Originally Posted by Daaan

May come because the car closes down the air vent holes so the air can’t get out. You notice that if you turn off the car copletely and keep siting in it for a while. After some minutes you will hear some noise, hard to explain, like if you put a CD or take it out of a CD player, just longer.

Also if a USB with a LED is plugged in (armrest), the LED doesn't die when you switch off the engine. It only dies after a couple of minutes.

[MagnusT]

Originally Posted by andrewc89

Make sure the recirc is off and crack a window.

The mechanic said to test with recirc manual-off compared to auto to see if there was any difference. But there was none when I was testing.

Yeah, opening the window slightly will of course work But I'm just baffled since no other car I've ever had has done this in this extreme way.

So I'm wondering if something is broken or if BMW just made a very bad design somewhere in the system, way worse than any BMW I've ever owned before. If no other M2 owner experiences this this points to something broken in my car.

[No one]

Originally Posted by MagnusT

BMW has checked the car but all electronics and mechanicals in the ventilation system reports back with no errors.

I'm not sure what I should do next.

Are you sure the cabin air filter ("microfilter") is clean? I can't see it mentioned in the thread (too obvious?) but it's a notorious reason for windows fogging.

[MagnusT]

That's interesting! But can it clog up in only two years? Definitely going to follow up this!

[M3 Adjuster]

Originally Posted by MagnusT

That's interesting! But can it clog up in only two years? Definitely going to follow up this!

of course it can. your car is NOT a new car if it is 2 years old.