Might be some carbon build--
@KayTwo had mines for a while and then it stopped mechanically working. Henry at Alpha walked me through how to remove the motor to check it... it's been a while but I believe it's three screws that hold the mechanical motor to the muffler. I removed it and checked to make sure the motor was operating properly. Inside the muffler is a GEAR that activates the door to open or close. Use your hand to see if that gear can be moved easily and if you hear that same noise... if it's hard to move you might have some carbon build up. Use some WD-40 or something like that to spray into that gear area... loosening and dissolving some of that stuff to make it easier to open and close it. That should solve the noise your hearing.
Thanks, man. We started to remove that motor last night, but I wasn't sure if that was the right move, and since I didn't have any drawings or guidance, I stopped. I will pull it off one of these days and do that and see what happens.
