Moisture Issue E30 85 318i

[vtmatt]

So as I was going through the process of upgrading my car audio, i discovered that both the passenger and driver doors had some mold/moisture issues. This was discovered after removing the door panels and noticing mold growth on the plastic door seals. Do I need to re-install these door seals? How can I prevent moisture buildup in the doors? Right now there are no visible signs of rust and I hope to keep it that way. Thanks in advance for any help or guidance.

[FredK]

Check the drains at the bottoms of the door. Moisture inside doors is REALLY common, especially for cars parked outside. The top window seal is likely allowing more moisture inside the door than when the car was new, or the drains are partially obstructed, or the car just lived in a wet area, like in the shade of trees.

The door seals are also likely vinyl, which is not a very mildew resistant material.

[vtmatt]

Thanks for the info. Is this something I should rustproof? I bought a couple cans today and have dried the doors and cleaned. I've never done before but im guessing you just spray and let dry?...thought u might know. thanks

[Mike325]

You don't really need to rust proof inside the doors. If you see any bare metal, then I would touch that up, but no need to do the whole thing with rust preventative paint. You could just replace the door's inner plastic and then maybe the weatherstripping around the door.