E46 Window Regulator Repair

by Jerry Skene


    You can quite easily repair a broken window regulator on your BMW E46. Read on.

    The first window regulator failure on my wife's 2000 328i was covered under warranty. When it happened again, the warranty had run out, so I decided to see if I could fix it myself.

    It turned out to be the rear slider that pushes the window up and down. The window uses a single cable that snakes between the front and back window rails. There is a small metal cylinder that is crimped onto the cable where it passes down each rail. This cylinder is responsible for pulling the window up and down. It fits into a plastic clip that in turn is attached to a metal bracket that screws on to the front and rear lower corners of the window.

    The problem this time (and probably last time, as the symptoms were the same- crackling noise followed by jammed window that will not go up or down) was that one end of the plastic clip broke, and the cylinder came out. This prevented the rear of the window from going up, so the window jammed.

    I decided that it was easier, and much cheaper to fix the clip than to replace it. I re-inserted the cylinder into the broken clip and held it firmly in place by using 2 nylon zip ties, threaded through the metal bracket. (I plan to do this to the front clip as well, as a pre-emptive measure. Maybe I'll do the remaining clips on the car also.)

    I have included a picture of the window mechanism - removed from the door, and also a close-up of the repaired clip, below.

    Note: In some instances, the airbag warning lamp may come on when you reconnect the airbag.  If the airbag lamp does come on, it can be reset by the dealer or a shop with the appropriate tool. To avoid this, you can disconnect the battery before beginning this procedure, and reconnect it after plugging the airbag back in.

    To remove the window mechanism (see photo below):

  • pry off the door trim piece (fake wood on my 328i, metallic plastic on my M3), using a small flat screwdriver
  • remove the two Torx screws (#10 or 15)
  • pry off 1 plastic cover on top and 2 under the door handle
  • remove 1 Torx screw under each cover
  • slide a slot screwdriver or other thin, stiff object between the lower edge of the door lining and the door, and pry it off so the plastic clips attaching the panel to the door pop out of the door.
  • pull the panel away from the door, popping the other clips out
  • pull the upper edge of the panel away from the door, releasing it from the clips, and lift up so it clears the door lock button
  • disconnect the door latch cable from the panel by rotating it away from the panel
  • unplug the speakers
  • remove the door panel and put it in a safe place
  • unscrew 3 10mm bolts from the side airbag
  • remove airbag from door, and unplug yellow connector. Put this explosive device in a safe place.
  • remove unidentified black plastic control box from front section of door (2 Phillips screws)
  • carefully remove the black foam moisture barrier on the door, trying not to tear it
  • move the window up/down such that the two 10mm nuts at the bottom corners of the window are visible through the front/rear slider rails and door panel. If the window is jammed (which it is, or you would not be doing this - unless you are smart and doing this before the window mechanism breaks), you will need to use a combination of the window switch and pushing/pulling by hand to move the window into position.
  • remove these 2 bolts - the nuts behind them can then be removed also, or they will fall into the bottom of the door
  • remove the 5 10mm nuts holding the window regulator to the door
  • cut 2 nylon zip ties holding the window cable to the door frame
  • remove the rear rail from the door by twisting it out
  • remove the front rail (you should install zip ties on both front and rear rail)
  • if a clip on the rail has broken, push the metal cylinder on the steel window cable back into position in the plastic clip
  • using 2 nylon zip ties, as per photo below, attach the cable to the metal bracket
  • reinstall motor/front rail
  • reinstall rear rail
  • re-attach window to sliding brackets
  • reassemble door panel

  • Photo of disassembled door, showing window mechanism

Close up of broken clip, with nylon zip ties installed

This repair has been working for several few years now, with no problems.

Happy motoring!

Check out my low-profile front license plate holder. No holes required in the front of your bumper.