Clunking vent noise
When I change the air from outdoor air to indoor air the vents make this
weird clunking sound. Its almost like something is opening and closing.
Actually, it reminds me of when you are vacuuming with just the wand and no
attachment and you accidentally get the edge of the rug or something and it
makes a "ffwwwwump" sound and you have to manually free the rug. The
car vent will make that fffwwwump sound loudly several times before I get
freaked out and switch it back to outdoor air.
Any ideas? I have looked online and haven't found anything.
Vents are blend doors and they operate by actuators. The actuator for this one door is defective and not closing the door completely. Just find the defective blend door actuator and replace it.