[airshane]

So I'm not sure if I have a problem or if this is normal, but when I select the "Auto Recirculate" function on the climate system there seem to be some odd things taking place. I'll notice the sound coming out of the system to change as if it's switching from internal to external air quite frequently. Has anyone else experienced this, or is this normal? It sort of gets loud for a few seconds then levels out, a minute or two later it does it again.

Thanks.

[lopealle]

i dont even know what that is. but im gonna ask you. is it when you have air come on at a certain time to push out air from the car?

[Kevin Harney]

I have noticed it too I think ... kind of a hissing noise ? If so I guess it is normal. I used to notice it in my Jeep too but never attributed it to the auto recirculate function before this ...

[MrDummy]

Is It BEST to leave the auto recerculate button ON all the time, or leave it OFF?

Or leave it off in winter and on in summer

[3er BMW]

Originally Posted by MrDummy

Is It BEST to leave the auto recerculate button ON all the time, or leave it OFF?

Or leave it off in winter and on in summer

Leave it ON.

[rkan]

I thought the in that mode the car "sensed" pollutants, and automatically changed to interior air, then back to exterior when the air was "good".
I tried it when I first got the car, but could not stand the constant "air flap" changing from outside to inside. Its an annoying sound change. It did react to stop and go exhaust fumes though.

[MrDummy]

^^ thats what the manual says it does. the salesmen told me he Always leaves it on, but I dont care about pollutants as much as having it correctly work in the winter/summer

Here is what Manual says:
Left-hand LED on, AUC mode: a sensor
detects pollutants in the outside air. If necessary,
the system blocks the supply of outside
air and recirculates the inside air. As
soon as the concentration of pollutants in
the outside air has decreased sufficiently,
the system automatically switches back to
outside air supply.
> Right-hand LED on, recirculated-air mode:
the supply of outside air is permanently
shut off. The system then recirculates the
air currently within the vehicle.
If condensation starts to form on the
inside window surfaces during operation
in the recirculated-air mode, you should switch
it off while also increasing the air flow rate as
required.
The recirculated-air mode should not be used
over an extended period of time, otherwise the
air quality inside

[F32Fleet]

Originally Posted by airshane

So I'm not sure if I have a problem or if this is normal, but when I select the "Auto Recirculate" function on the climate system there seem to be some odd things taking place. I'll notice the sound coming out of the system to change as if it's switching from internal to external air quite frequently. Has anyone else experienced this, or is this normal? It sort of gets loud for a few seconds then levels out, a minute or two later it does it again.

Thanks.

Normal

[Nr!qUe]

When i was test driving the car a while back i asked the salesman where the air should be because i'd seen the same thing on my sister's car, she has the same car.

He said "You know how sometimes on long drives you can get a headache? It's because the same air in the car is recirculating and the air quality decreases." He said that it should be left on Auto because It refreshes the air in the cabin every once in a while.

When i get behind a diesel truck or when i'm about to drive through a cloud of diesel exhaust, I just turn my air off.