Thanks, I don't know what is moving but I'm guessing it is the temperature regulation flap since the air does not seem to change where it comes out when making noise and I don't hear it in the first few min of driving.

I was thinking that if the temp flap has a position sensor, perhaps it is failing and the controller is cycling thinking it is where it but really isn't. As a side note, the HVAC control panel is the same as a similar year SL, just the version coding is different.

I don't drive this car much as it is Moms summer car and lives at my house during the winter. Will try to see if moving requested temp makes a difference.