irritating problem with my 318 window

[john18]

SO i bought a 95 318 is. I bought it knowing the passenger window didnt work. You could hear the motor whirring but the window was just not moving. You can manually move it though. So im popped off the door panel and i see that the motor isnt even connected , and im gettin all excited b/c i haggled the guy down for an easy fix. I put the motor back in place and i roll down the window. works like a charm. then i try rolling hte window back up and it works like a charm. then about halfway it abruptly stops and the motor makes a horrible grinding sound. SO then I have to pull up on the window while the motor is working to get the motor to get out of its "bind" and it will do this grinding thing a few more times before the window is completely up.

Ok so heres my question. Is there something stripped in my motor ? Or could it be the window regulator. I did a search on it here and i found that the window regulator was a common problem and alot cheaper than ad new motor. And also what IS a WINDOW REGULATOR?

Sorry if this has been beat to death. Pease Help. -John

[Tim Polzin]

John:

I was just looking at the Bentley manual. The motor appears to have a worm gear which drives the window regulator. (BTW, the "regulator" refers to the multi-arm contraption that raises and lowers the window). There are a series of teeth on one of the arms of the regulator. My guess is you have sheered off a few teeth on this arm, some of which can just be seen on this picture.



Ignore the green circles as I borrowed the picture from another source.

Good luck....Tim

[john18]

all teeth are lookin great so i guess thats not hte problem

[blkongry]

Yep, familiar with this problem. I have it with my '94 325ic. It is a worn part, but I haven't pulled it all apart yet to see. My guess is that it is a gear interface. With my car, the window rolls up and down flawlessly, but when it gets to the top, it gives that nasty 'BRRRRRRRP' as it bumps up against the upper limit stop. Now, when the weather gets really cold, it slips and brrrps like your window does sporadically as I roll up the window and I have to assist it.

I don't think this problem is associated with the regulator. If you look at this picture, you can see where the worm gear comes out of the motor and into the window drive mechanism. I think the problem is internal within that mechanism... most likely a brass worm gear off the motor wearing against the teeth of the mate motor.

If you get the door apart, press your fingers on the motor in this area as you roll the window up and see if the vibration associated with the noise is located in this area. My guess is that it is, and you need a new motor to get the whole assembly.

Let me know what you find... I'm going to have to do this to mine soon.

[blkongry]

Hmm... is there a set screw on the end of your motor drive? I wonder if there is a way to increase the gear engagement like on a steering box. that should remedy the problem (for a while).

[john18]

thanks for hte help fellas i'll let ya know how it turns out

[john18]

welp i must be unlucky. Pulled the passenger motor off a '93 318is to put on mine. Did not match up. The terminals (if thats the correct term) that connect the motor to its power source did not match my car. IM baffled. I hope i dont have some ghetto rigged electrical system in my car

[blkongry]

If you can track down the polarity, you can just wire in an intermediate 'adapter' to get that motor to work... just to see if it works, and to ensure the problem goes away. Did you buy the '93 motor? Can you take a pic?