BMW Repair: Power Window Failure 1993 325is, white lithium grease, wheel bearing grease

Question
The driver side power window will intermittent fail to either lower or raise.  At times when the window is open and I attempt to close it, it will rise a bit, stutter, and start to lower itself.  To get around this I have found that buy depressing the window switch in short, rapid bursts, the window will close.  I can hear the motor click within the door panel every time I depress the window switch.  What do you recommend?

Thank you
John

Answer
John, I recommend replacing the window regulator, motor and the two white plastic sliders that attach the window glass to the motor. You can try replacing just the motor and the white sliders because if I remember correctly the motor bolts to the regulator from the back side meaning that the window regulator has to come out to change it. On a car this old I change all three because a sticky/binding regulator can damage the motor. The motor is riveted in and you will have to drill them out to remove it. I recommend bolting it back in and locktiteing the bolts or using nyloc nuts. If you can get to the motor from the front side then try that first, but the motor is the more expensive of the two items. You could take the motor and regulator out and then put the regulator back in to check if the mechanical mechanism is binding without the motor, proving only a defective regulator, but It isn't worth it in my opinion. This job is a bear for the inexperienced, just depends on your mechanical ability and dexterity. I charge 3 hours labor at the dealer and it is not my favorite job by any stretch (I'm not trying to scare you).
If you do replace them yourself here are some tips:
Carefully remove door panel
Don't tear plastic or foam vapor barrier (it keeps water out of your interior and need so go back on and seal
Install new regulator with scissors pointing up
Clean out metal channels well and lube channels and white sliders with good high temp. wheel bearing grease, not white lithium grease (this grease turns yellow and hard over time).
Install sliders into channel first and then pop them into the regulator, not the other way around.
sliders make a LOUD audible pop when they fully seat to the regulator ball.
Test operation before reinstalling door panel.

-Evan