Rear window just fell...out of the blue

We're driving along...hear a bit of a weird sound (like a rock breaking some glass) and the rear passenger window (e46 sedan) just fell down open. It won't roll back up. I lifted it up manually but it won't stay up. When using the switch to roll up and down it sounds like there are little rocks/broken glass in the mechanism.

I assume the unit has failed and my 1st course of action is to remove the door panel and replace it. Question is...is this normal? Wasn't a bumpy road or anything...we were just driving along and decided to roll down the windows when "pop"...this one made that breaking noise and fell.

Mine fell when I came to a stop.
Window regulators are a weakness on our cars, you can buy the assembly online and its an easy DIY
I got mine from fcp, you might be able to find one on ebay
Sent from my VM670 using Bimmer App

Id caution against ebay crap regulators. I have seen 4 fail right out of the box.

Oembimmerparts.com sells the good ones

Originally Posted by KSims1868

We're driving along...hear a bit of a weird sound (like a rock breaking some glass) and the rear passenger window (e46 sedan) just fell down open. It won't roll back up. I lifted it up manually but it won't stay up. When using the switch to roll up and down it sounds like there are little rocks/broken glass in the mechanism.

I assume the unit has failed and my 1st course of action is to remove the door panel and replace it. Question is...is this normal? Wasn't a bumpy road or anything...we were just driving along and decided to roll down the windows when "pop"...this one made that breaking noise and fell.

Window regulators fail regularly on these cars but most of the time the glass stays in place. You'll have to take the door panel off to make the repair. You will want to make sure the window moves freely in its channels before you connect the regulator to the glass. Lubricating the channels with some silicone might be a good idea. It's an easy DIY and plenty of help is available by searching for "E46 window regulator"

Get the window up and into place and then put a thick bead of Liquid Nails on both sides all the way around. Should stay put after that.

Originally Posted by KSims1868

...Question is...is this normal? Wasn't a bumpy road or anything...we were just driving along and decided to roll down the windows when "pop"...this one made that breaking noise and fell.

Unfortunately, the answer to your question is: yes this is normal. The window regulators are a known weak spot on the E46 models. My right rear window sounded like a gun shot when it failed. It was loud enough that I was concerned about damage to the inside of the door. When I pulled the door apart, the regulator cable had "exploded", but there was no other visible damage. A new regulator fixed everything.

I went ahead and replaced both of my rear regulators. I had previously replaced my front regulators. They are not terribly expensive, and replacement is a reasonable DIY project. To repeat the advice of Smolck: beware of inferior replacement parts. I used genuine BMW regulators.

For some reason the right rear regulator seems to be more prone to failure than the others. I am unable to explain why.

Originally Posted by alpinweiss

My right rear window sounded like a gun shot when it failed. It was loud enough that I was concerned about damage to the inside of the door. When I pulled the door apart, the regulator cable had "exploded", but there was no other visible damage. A new regulator fixed everything.

This sounds like what we heard too. Looks like I have my 1st Bimmer project!!