Door window

Making a guess, the slides that the window rides on are sorta like a felt material bonded to metal brackets. If that stuff comes off and it's glass against steel, you'll get noise. Going the other direction they might not be touching due to the direction of forces. That's a possibility.
There are scissors tracks that raise and lower the window. These have pins with ball ends that go in sockets to support the window. The pins are probably a total of 1" length, they have a "rivet" end that rivets to the tracks. I've had those rivets work loose and even break off and do some strange things, but that's usually associated with poor window alignment. You can also grab the window when it's half way down and it'll have slop in it (up/dn). If the movement seems excessive, some part in your window hardware is broke.
I suppose a motor could do that but why going down... I have no idea.
The regulator cable is binding when it moves in the opposite direction.
There is a plastic tube that usually breaks that keeps the tension on the cable.
You may consider replacing the entire regulator and motor for about 80 bux at rockauto.com
Easy job you can do with posts here and youtube
I am not sure what the poster above is talking about.
I bought the GM part and it has worked perfectly. When you replace your passenger door windows regulator (and you will) - be aware that the connector has changed. You will need to cut off and replace the wiring connector.
This is an easy fix, but be sure to put tape on the windows (and the window trim) to mark its position. This helps a lot.









