I have an 18 year old suburban I use to make runs to the hardware store. Plywood, piles of rock, plumping parts, etc. It has been slowly degrading with an increasing number of cosmetic blemishes and features on the fritz. I normally don’t mind these too much, but I had a really odd one. I opened up the door after not having used it for a few weeks and there was mold EVERYWHERE! I needed to pick up stuff that day, so I cleaned it all and moved on with life. I thought it must have been raining or something the last time I used it.
I made a vow to drive it more often and didn’t think about it. I did notice though, that the windows were always fogged up every morning. Everything was super humid inside. I got in one night when it was raining to look for a leak and couldn’t find a thing. I crawled all around and finally got over to the driver side. The carpet made a sickly squish sound. It was soaking wet.
I saw water drops under the dash, but could never locate the issue. Took it to the mechanic and they said it was a deteriorated windshield seal. Got the windshield replaced, still more water showed up when it rained. Now I had all the dash bits apart and I could see it was coming in from high up on the A pillar. It actually looked like it was coming out of the folds of metal around the frame. I thought the roof rack was leaking water into the layers of metal that make up the roof.

The screws were all incredibly rusted, and the threaded segments in the body were in poor shape as well. I pulled everyone off, cleaned the area, replaced all the hardware with fresh stainless and caulked everything. Leak check? Yep, still leaks!
I had been trying to use fans to dry out the carpet, but this was the point when Dorian was bearing down on us. After we got setup for the hurricane I started going through and pouring water around to see if I could induce the problem. Pouring water on just the driver’s door seal would cause it to leak out of the windshield area. Pulling the door seal off I noticed it was in rough shape, and behind it was seams of metal.

I think what is happening is that water gets past the seals and rides in the bottom of that U channel the door seal makes and gets soaked up into the seams of metal. The top of the door is higher than the A pillar.

Water starts up high on the door seal, soaks in, and comes out starting near the upper part of the windshield (blue arrow). The picture below shows it from the inside. It comes out along the whole A pillar, starting up at the top edge.

To remedy this issue I put some flowable silicone in a syringe with a thin plastic tip and shot it all along the drivers and passengers side door seams.

I ordered new door seals and when they came in I removed the old ones. It turns out there is a U shape of metal in there that helps keep everything clamped and sealed to that inner lip of the door opening. The metal had fatigued and wouldn’t hold the seal shut anymore. Dry rot on the rubber didn’t help.

The new seal fit nicely on the door opening lip, and was new and puffy enough to make the door slightly harder to close. It seals well now! Through a minor rain, carwash, and direct spraying with the water hose nothing has leaked in.

It took forever to get the carpet dry. The padding underneath was super soaked and I couldn’t figure out how to remove it. Eventually I just put my dehumidifier in the truck and sealed it up for a day. It got hot and dry and eventually moved all that water out of the carpets. Hopefully it will stop smelling like a bog and attracting frogs from now on out.