[Rob_G77]

How to deal with window smear? Any time I wash the car, the driver side window starts smearing like in the enclosed picture. Even later when everything is dry, it still smears, but not as bad.

Rob

[John in VA]

Is there something on the weatherstripping leaving this mark? Window mechanism or vapor barrier? I'd take the door panel off to investigate.

[///MPhatic]

There are various guides that are (usually) felt-covered in there, you've probably lost one (no fault of your own), so the door panel has to come off to find/fix it. Have a pair of disposable gloves handy, it's a dirty job because of the sealant they use. I've never taken my BMW door panel off, but they're all pretty much the same.

[spammysammich]

if you pull the vapor barrier off make sure your get some 3m Window Weld or other such butyl tape to make it water tight again, this is very important.

[John in VA]

When working with the vapor barriers I try to do all I can by pulling it down from the top & sides, without removing the bottom edge in hopes that they won't leak later. A heat gun helps make the butyl caulk adhere better.

[swainbmw]

Originally Posted by John in VA

When working with the vapor barriers I try to do all I can by pulling it down from the top & sides, without removing the bottom edge in hopes that they won't leak later. A heat gun helps make the butyl caulk adhere better.

These new cars don’t have that anymore unless it’s behind this plastic shell when you take the door panel off with my experience, installing Removing the door panel to get to the speaker it’s not like a plastic vapor barrier that you use to find when you took the door Panel off . Almost like a composite shell

[John in VA]

Originally Posted by swainbmw

These new cars don’t have that anymore unless it’s behind this plastic shell when you take the door panel off with my experience, installing Removing the door panel to get to the speaker it’s not like a plastic vapor barrier that you use to find when you took the door Panel off . Almost like a composite shell

I've not had to dig into the F22 or F30, yet! E39 & E46 have shaped foam vapor barriers that need to be detached to replace the window regulators.

[GOLFFRR]

have you checked the area where the window rolls down into your door? the material that protects the window? could be something like a bug or something caught in there so every time it rolls down its getting impacted by whatever is in there

[christianb5s4]

Start simple first before tearing things apart. Put the window all the way down and use a damp microfiber cloth (with some diluted all purpose cleaner) to clean the seals where the window slides up and down and see if that helps.