Knocking Noise near Glovebox
 

I am getting a knocking noise near my glovebox occasionally. However since I have turned off the temp. control, the knocking has stopped thus far. Is there something like a valve on the windshield/floor outlet in that area?

And this is a??????????



Model and year please, pretty much all of 'em are different.

It is a 89 300E. Sorry for the oversight.

Could be the aspirator motor. It's a small motor near the glovebox which connects to a foam tube that goes to the cabin air temp sensor in your courtesy light. The fact that the noise disappears when the climate control is turned off makes me suspicious, although when the aspirator motor fails it usually just seizes up rather than making knocking noises.