passat 2002 rattling noise when heating

[passat.2002]

There is a rattling noise coming from the front air vents? when the heating works, it stops immediatley when i turn air-conditioning off. Never happens when cool air comes in the car. Any ideas?

[aralev]

Hey, I have the same issue, did you ever fix it?

[veedubmechanic]

could have some leaves stuck in the vents, its easy to get leaves in the ducts when the pollen filter is removed. Is it a weak tapping noise? if so the blend air doors may need to be reset to basic setting, its done with a vw scan tool.

[aralev]

Hey! That's exactly what it sounds like, does that mean I need to take it to a VW dealer who has the scan tool?