2017 F-150 SCREW.

After some recent heavy rains in So Cal I noticed - and have noticed in the past - a strong mildew smell. Finally decided to seek out the source (which I should have done much sooner) and eventually pulled up my driver's side door sill plate to find the wire guard channel full of standing, gunky, green/brown water. It was gross. The water did run back under the rear sill plate, too, though not as much. The carpet under the driver's side was dry except for a small patch near the stomp pad, which I dried out thoroughly. No other portions of the carpet were wet.

This is only on my driver's side, as I checked the passenger side and found it completely dry.

Some info: no sunroof, no sliding rear window. I do have an aftermarket third brake light I put in a few years ago, not sure if that could be a possible culprit but the housing has never shown any signs of water retention or droplets and the seal is tight. The windshield vent liner seal is pretty much gone on the left side, meaning water can run down the windshield and pass through with no issue. The right side is still sealed tight. My driver's side door handle seal (that worm-y white rubbery seal inside of the handle) deteriorated within the last few years but Ford quoted me at $350 to replace it (absurd) and I never did. It did not appear water was leaking in through there and into the channel.

Rain is expected again next week and I'd like to narrow down the possibilities of where the water is coming from. I have ordered a windshield sealant and plan to fully patch up any exposed areas tomorrow. Would like to hear any other areas I should check so this issue can be properly fixed, which I am comfortable doing on my own.

Thanks in advance for any assistance.

 

There is a pinch seam in the cowl area. Not sure if there is one on each side. There have been postings where some trucks got out of the factory without any seam sealer in the seams. You might want to look at that.

 

Check your rear cabin vent. Also the splash shield on the door, either door could do it.
These videos might be of assistance:

 

Thank you for these. I'll check both. I'd love to be able to fix this myself since, from the research I've done, it seems the dealer will have a hard time replicating the issue and likely may not actually repair it. And I don't want to give them hundreds of dollars.

I did see a thread on here where someone found the cowl seal wasn't done properly and did it himself. I did a preliminary look under the cowl today but wasn't quite sure what/where to seal, if anything.

 

I've actually never seen one of those cowl leaks. And I do leaks for a living. I don't know if it was an isolated run of trucks in a certain part of the country or what, but pretty much nobody other than another leak specialist (and there aren't that many) sees as many leakers as I do and I've never seen one. I don't think it's that common.

In the videos, I show you how to test and see if it's from the door. Even if you don't want to fix it yourself, you can at least know if that's what it is. It's very easy to test.

 

Pacfanweb, thank you very much for the videos. I did your tests and it seems like it may be a door panel leak. I'm going to try removing the door and seeing if I can reseal that piece myself. If I do need to apply anything to it I'll just run to Lowe's and get some butyl tape and see if that does the trick. The lower drains seem to be working properly, so they aren't clogged, but clearly there's something going on inside the door.

 

Follow up question: could the door handle gasket seal have anything to do with water entering the door? Most (all?) of mine seems to have eroded in the last few years. Some research I've done online indicates the seal is only there to hold the handle in place during installation but would it be sensible to remove the handle and apply sealant, or is that not necessary?

 

Sure. But water is SUPPOSED to get inside the door, and it's supposed to just exit out the drains in the bottom of it.

Trouble is when the inner splash shield come unsealed from around the openings behind the panel, instead of just deflecting off it and back inside the door, water can get into the door panel and spill over the scuff plate into the interior.

I don't know if you can get the butyl tape at Lowes, I usually get it from parts stores. They might have some version of it. I use 3M.

 

Took the door apart today and immediately noticed the seal Ford used was eroded on the bottom edge. I went ahead and resealed the entire thing with butyl, did the water test again and the seal did its job. Drains at the bottom both flowed just fine so hopefully that's the end of this problem. It's supposed to rain in So Cal next week so I'll find out for sure soon enough. Thanks again for the help.