Hvac flapper noise / clicking loud

[mjimport]

I am still trying to identify what conditions produce the noise, however it seems to be noticeable in the hotter and humid weather. It sounds like the flappers are sticking and "clicking" loudly when changing vent options (from defrost to feet for example).
has anyone had this happen? Does it get worse, stay same for years, or eventual catastrophe ??

[shogun]

the foam has disintegrated and must be replaced , if you want to fix that, but I assume you do not want, as you have to remove the IHKA unit, see here some pics from the E31 http://www.km5tz.com/BMW%20850iP4.htm

[mjimport]

Wow that's a lot of work, maybe when other projects are done I'll tackle that. It reminds me of the Infiniti G35 console/dash I disassembled a few years ago. Very tedious work.

[shogun]

another possibility is that the stepper motor clips are weak, here we made a youtube on my spare unit https://www.youtube.com/watch?v=pCzW...1&feature=plcp
I fixed it with zip tie some years back and still working. A quick test: remove the grill on the dash center, 1 or 2 screws only, then switch the IHKA system to only up , down etc and see if the flaps are working.