Tap tap tap tap tap ...........
Nothing tooooo serious but annoying. A few months ago one Saturday early last October to be precise, a tapping sound started coming from what appears to be the ventilation system. Every time I start the ventilation either through switching between external and recirculated air or vice versa, or through starting or restarting the car, this tapping noise occurs and continues for about 20 or 30 seconds. It is less noticeable if I switch to the recirculated ventilation but it is still there in the background. I have assumed it is a 'broken' gate but I really don't know.
Can anybody help me with pinpointing the precise problem and with any advice on how to repair it?