Corsa-B.uk - Vauxhall, Opel and Holden Corsa B Owners Club

Hi, I was testing the operation of the flap inside the airbox housing earlier today. It is open when the engine is turned off, and then closes when I start the engine.

Is this right? Could somebody please explain to me the way it operates? When does it open to let in cold air from the feed?

Thanks

Alex