BMW Z3 power window problems
Why does the Z3 power window go down slowly or jam?
Usually the window guide channel has dried out or got dirty. Spray thin oil into the channel, move the glass back and forth by hand and clean the glass and the seals. The lubrication lasts only a short while and has to be redone after rain.
What else can be behind a sticking Z3 window?
The regulator bolts and nuts may be loose, or the mechanism is worn. Tighten the mountings and lubricate the moving parts. If the mechanism is broken, the whole regulator is replaced. The glass retaining clips can be ordered separately, and the plastic clips should be renewed if the glass is held at only one end.
Why does the Z3 window not go down when the door is opened?
On the roadster the window is not supposed to move when the door opens, while on the coupe it drops. If the coupe's window does not react, the door microswitches may be confused. Disconnecting the battery for a moment or running the windows fully up and down a couple of times with the auto function can help.