Ok so we're back to square one

Mine (pre-LCI) don't have a motor, they are freely movable when the car is shut off, and are held closed by the magnets (solenoid switches) when engine is working but cold.

I will have a look if, when the engine is hot, they are opened up by the air current created by the fan, and post here.

 

I will try to see if I catch the moment again