A Pillar Leak Not Sure of the Cause

Hey all, I have a 2016 double cab off road that I just discovered a leak in. I noticed I had a small pool of water on my husky floor mats, so thankfully the water didn't get under that into the carpet. It seems my roof where it connects to the passenger A Pillar is pretty wet, and it seems to be dripping down the pillar to the right of the glove box, and directly onto my floor mat.

I opened up the cabin air filter box and its bone dry, but I noticed a couple drops on the box cover, that has the rubber flap. No leaf or debris in any of my drain ways that I could see. Truck has been sitting for 2 days and it's been raining on and off. Rear seat roof is all dry from what I can see.

I have a moon roof, and everything looks fine. Nothing blocking the drain holes in there. My door seals seem good, and I don't have a roof rack and that roof liner still looks solid. No windshield replacement either. I'm kinda at a loss figuring out the cause. I will be taking it into the dealer on monday but they are super swamped from all the fuel pump recalls.

Any ideas where this could be coming from? Thanks!

 

Check the metal bracket on the drivers side that wraps around the obd2 port for surface rust...a tell tale sign it leaks there as well. If that’s the case you will be pulling the windshield, dash and both fenders to fix it.

 

Just looked in there and everything looks fine. The truck has always been garaged and this is the first time it's been outside more than a few days while it's been raining on and off. I checked for dampness all over and the only source seems to be right above the passenger a pillar.

Truck is parked on a level plane right now as well.

 

I'd check all the seals around the moon roof.

 

Took a look at the seals with it open and closed and they look good as well. With the 2 water outlets towards the front, does the moon roof allow any water in while it is closed? Or are those channels more for when it is open? I did notice water in the channels after opening it but looks normal, unless there shouldn't be any since it's been closed.

 

On day 4 at the dealer now, and they still can't find the leak. The first 2 days the tech was only spraying the back of the roof, no where on the front since the service rep mistakenly told him the back window was leaking, and not the front.

Not sure what to do at this point. The windows were completely closed, and the water only appeared on the floormat. I already am out 4 days for a rental and diagnostic fee.

If it leaks again, what do you suggest I do?

 

Stuff the hose at the base of the windshield cowl area and you’ll find it that’s the easy part...fixing it will require a loan good luck

 

Grab a hose and check everything to rule it out, one at a time, water leaks can be tricky.

 

Good to know! Would that area still be a factor if the ceiling material right above the passenger A-pillar was saturated?

Not sure how the tech is doing the testing but can't believe he still hasn't found anything with a hose.

If they find the leak, my insurance will cover it all minus my $100 deductible.

 

I had this exact leak, but for me, it was from the roof rack. The silicon held good for one winter but not the next. Do you have a roof rack?

 

Nope, no roof rack. It's all stock up there, so I know that doesn't make it any easier to figure out. Only thing I really modified was adding in an O+ audio system where I had to get into the pillar, but that was 3 years ago.

 

Had this with my last f150 and one of the reasons I sold it. Finding leaks is the worst. I just used to sit there with a hose and let it run on certain areas and wait for a leak. It helped track it down but if its dripping from A pillar to under the dash its gonna be a pain

 

Any chance the factory seal over the roof rack holes has failed? I’m not sure the weatherstripping keeps all the water out of the channel.

 

Did they check the drain tubes for the sunroof?

 

Yup, they said the drain tubes were clear. They looked fine to me as well, and had some moisture at the tube openings when I checked.

 

Did you try pouring a small amount of water to see if the drains actually drain all the way through? If there's a blockage down the line, it would fill up and not drain then overflow. If you have compressed air, might want to blow them out just in case.

Other option is to start popping trim to see if a drain is busted or top of windshield is leaking down somewhere. You'd think the diag would've checked the easy stuff but then again...

 

Had the same issue and place for the leak after I took my truck through the car wash the other day.

Going to watch this thread to see if you find yours.

 

Thats a good idea! I will definitely do that when I get the truck back if they don't find the leak. Is it normal for water to get pas the closed sunroof seal and go through the drains?

They finally got the service manager involved, so hopefully they get more techs on it. They also finally said they will only charge me for the rental for one day which is great. They can keep the truck as long as it takes to find the leak haha.

They keep making me feel like it was my fault it leaked, but if others are having the same issue then it must be pretty common.

 

Just to throw another wrench into this, but I don't have a moonroof and my leak looks identical to yours.

 

That helps narrow it down though haha. I don't think it's my moonroof either. The fabric right above the a-pillar plastic piece was super saturated but wasn't more than a couple inches back towards the rear of it. Truck was on mostly level ground.

Directly below the glove box, basically right above my little puddle in the picture, I put my finger behind the plastic knee part, that slopes down towards the back of the floor area, and there was water all over it. So it was coming from somewhere above that after the pillar area. The whole thing is super strange. I wonder if maybe the roof trim fastener maybe has the leak or something. Seems super specific right above the pillar.

I'll see what they say tomorrow, but that they probably still can't find the leak. They need to take all the paneling off to find it.