My '92 300e started having a wind noise coming from the drivers side door that was driving me crazy. I tried adjusting the door hinges and stops but nothing seemed to help. A couple weeks ago the window regulator gave out and I had to buy a new one. After replacing the regulator the wind noise stopped. It appears that the teeth on the regulator were worn enough that the window did not close completely and was making the noise.

One thing I still don't understand is how the motor for the power window senses when the window is completely opened or closed. I'm assuming it has a torque sensor similar to a garage door opener that stops the motor at a certain torque. I did not see any limit switches or setting to adjust the amount of window travel. Any one have any knowlege of how these windows operate? - Just curious.

John