'95 525i. I know regulators have been discussed a million times but can't seem to lay my hands on the answer. My left rear goes "knock, knock, knock" when I try to lift... I can help it by lifting window, but it can't do it on it's own. How do I tell if it's the regulator versus motor? I did get the panle off and am looking at it. It's not the "clips", they look fine. At first I thought the round plastic thing, which I guess houses the gear, and the motor bolts to... came with the regulator, but guess it's really part of the motor assembly? Yes I know I sound confused.. I do have a bentley manual... but still confused... anybody want to show pity on me?

pop the regulator out of the plastic clips, and then pull the window up all the way. use a piece of tape to hold it there so you don't guillotine yourself.

make sure the window slides in the channel freely. if not you might need new rubber/felt window seals, or at least to clean/adjust yours.

double check the front window channel mount, there's a rubber plug at the front of the door to

then try running the regulator up and down via the switch. watch the arms to see if they are bent and possibly jamming. listen to the motor to see if it's straining.

in my experience motors either work, or don't. clicking/funny noises usually indicate broken gears, bent arms, or something mechanically wrong.

also double check that all the rivets are still holding the actuator to the door. one of mine had broken free, so the actuator moved laterally more than it should. i replaced the rivet with a 6mm bolt which helped eliminate that movement. good luck!

Thanks for the reply... the channels are nice and clean.... guess I'll have to get busy and remove it (rivets) to tell what's going on. Was hoping to pre-order what I needed before taking apart... because then I'll be stuck with the window down until the parts arrive. The teeth in the regulator look pristeene to me, and nothing bent, warped everything tight. Kinda sounds like the teeth in the motor gear are worn out.. as it seems to be skipping, but you'd think the softer metal would be the regulator teeth?dunno... anyway thanks for your help.. guess I'll get busy drilling.

If you need it, I have good, complete regulator/motor assemblies available. I ship stuff to Richmond with 2 day transit times via UPS.

Take apart another door and swap motors if you think the motor is at fault.