After 102k miles, my beast is starting to show her age! I recently heard a knocking from the passenger side, behind the glovebox. It is definately not a rapid click, but more of a loud knock, like someone knocking on the front door. Its only happened a few times and I havent been able to replicate it yet. When it happened, I was not using the heat or A/C. Heating controls appear to work normally.
Could this be the infamous dash woodpecker or possibly something different?
BTW, I have an '06 LE with auto climate control. I'm not sure if it makes a difference, but I have the geared valve in the engine bay.