wristshot

Sorry for another cab leak post, but after reading all of the others, none seem to address my issue.
I have owned my 2015 XLT F150 CrewCab, WITHOUT SUNROOF, since new and this problem has started in the last 6 months or so, now past the 36,000 mile warranty.
After every substantial rain event (maybe half inch or more), then baking in the Texas sun for a few hours, I have a horrible musty smell for several days. This odor does not occur after washing the truck or running the AC on long trips.
I've removed interior trim, in search for a leak, while using a waterhose to spray the outside without success.
I have removed the insulation on the cabin rear panel and don't see any evidence of leakage around the rear window or cab vents. The carpet back there is dry and without evidence of stains.
I have removed the A-Pillar trim grab handles and looking along the windshield seal, down to the lower corners - no evidence of leakage. I know others have mentioned leaking windshields.
I have removed the third brake light, the seal seems good and there is no evidence of water intrusion.
I have not removed the headliner, but there are no visible stains.
Door panels have been off, no signs of icky stuff, and I am not sure what would get wet in there anyway to cause the odor (just metal and plastics).

What I have seen, is water in the passenger side door sill channel several times, but the adjacent carpet is always dry. I have no idea how this water gets in the sill and even when it does how it alone create the odor.

Can anyone provide some direction on isolating and eliminating this?

junkyard08

Have you checked the SAT antenna?

wristshot

Thanks, I will check it. If it were leaking would the headliner be wet or stained? Any direct experience?

junkyard08

from what I have read, not necessarily. It travels down the pillar but can sometimes leak out of the grab handle as it travels. Im currently trying to track down a leak myself in the front. I found the leak in the rear. My leak up front is making the drivers side floor wet.

The SAT antenna is known to leak. You have to drop the front part of the headliner in order to get to the nut that hold the SAT antenna on. If you remove the antenna, just use RTV to create a new seal/gasket when you put the antenna back.

jrmccoy823

I had the same issue, well almost. When I first got my truck, 15 XLT I noticed the same smell. i took it to the dealership and they replaced the front windshield because they had to reseal around it. Once it rained again after this i would still smell the horrible musty smell. They never could find another leak, so I had to do the searching on my own. I folded down both rear seats and the carpet behind there was absolutely soaked and stunk. I took it back to the dealership and they figured out that it was the sliding rear glass. They replaced that and took the seats out and cleaned the carpet and let it dry good and the smell went away. You can also check the brake light and the vents that are behind the rear seats, I've read that some people have had those to leak. Hope this helps and sorry for the trouble you're having as I know what you're going through and how aggravating it is.

jrmccoy823

I will also say i could never get the smell to start by washing or running water over it, it was only when it rained.

phenrichs

Do you have a rear sliding window? I don't see mention of checking for leaks there. It is possible that it is coming in back there. In which case it is going to be down the back wall into the carpet. Those seats fold down. Easy enough to check.

motsco

check to see if cabin filter is getting wet

make sure ac drain isn't clogged.

kroberts2131

Dealing with this exact issue today actually. I can't find it and neither can the dealer. We had a big rain two days ago and it's terrible in my Lariat today. I am to the point of just rolling down the windows after a good rain to air it out.

wristshot

I do have a sliding window. I have lowered both seat backs, removed the subwoofer, and insulation panel. You can see pretty much everything. Using water hose I don't see any leaks around the window, window slider, or cab vents. Going to leave it apart for a rain event, but I may be waiting a while here in Texas. At one time I thought the carpet behind the rear seats stunk but it was not wet as far as I could tell.