Water Intrusion Issue - Resolved

[Intuit]

I did the same thing. Turned out mine was actually leaking from under the drip rail molding.

What's beneath the roof rail molding? I thought it was just sold body, no holes or access point for water??

 

[atlantaM3]

The roof panel meets the body side panel at that point. It isn't a solid weld line, there is body sealant under that strip. When replaced, they managed to peel away some of the body sealant, allowing water entry, the water ran down the inside of the body panel, and would come out where the panel meets just above the taillights and run then run into the car.

Was fun the track that down.

 

[Sam4]

Mine's somewhere along there too. Nothing until I go past the sunroof (nothing from the tail lamps), it works its way to the post for the 'parcel shelf', drips onto my weathertech mat and I dump it - ta da!
How does that strip attach? Locating tabs and adhesive?

 

[atlantaM3]

The drip rail trim is just a stick on piece. Gently warm to loosen adhesive to pull off cleanly.

The dealer apparently just yanked it off without heating it, as I could see three places where they pried it up. Thus pulling the body sealant with it.

Thankfully the parts aren't that bad. Expensive for what they are, but still tolerable.

 

[M-Sport fan]

The roof panel meets the body side panel at that point. It isn't a solid weld line, there is body sealant under that strip. When replaced, they managed to peel away some of the body sealant, allowing water entry, the water ran down the inside of the body panel, and would come out where the panel meets just above the taillights and run then run into the car.

Was fun the track that down.

That's why I just JB Weld epoxy that strip back down when the ends start to peel up, instead of replacing the whole thing.

I also 303 them extensively at least 6 times a year, to try and head off any total deterioration requiring replacement.
(My car is most definitely NOT a fair weather, weekend only, garage queen, and is fully out in the weather 24/7, 365, for it's entire life since new, and going forward.)

 

[Intuit]

The roof panel meets the body side panel at that point. It isn't a solid weld line, there is body sealant under that strip. When replaced, they managed to peel away some of the body sealant, allowing water entry, the water ran down the inside of the body panel, and would come out where the panel meets just above the taillights and run then run into the car.

Was fun the track that down.

Thanks for the detailed description. Wouldn't surprise me if this yet another issue caused by the dealer's work.
Hot-baked Summer sun it comes up with literally no effort. Still more work to do.
One of the towels I have surrounding the wheel well was pretty damp after driving through some heavy rain.
Re-added this back there until I will get back to it.

 

[Intuit]

Update: (the short details)
This turned out to be Sun Roof related.
The rear passenger hose had a restriction due to partial clogging.
My cell phone bore cam (https://www.amazon.com/gp/product/B071HYRPND/) spotted the clog in the rear passenger line.


More details:
A smaller bore cam would've made it farther down the line.
There was a small water pool in the spare tire well. Never found water like that, back there before. The towels I had back there are why there wasn't more.
My earlier testing weeks ago, opening the sunroof and pouring a cup of water down the trough didn't really reproduce the issue.
Water would immediately and rapidly exit from behind the bumper. I only saw water leave the trough if I poured what I thought was an excess of it. So paid the test little mind.
I could only reproduce the issue if I spent literally ten minutes watering my closed up car as if it were a lawn, while it was parked in a specific angle.

I removed the clamp altogether and will wrap the line with layers of electrical tape to prevent abrasion damage.
The debris corresponded with the location of a clamp; the only visible clamp out of all the lines that was visibly pinching the hose.
It's a surprise because the pinch was very minor.

Blew out all four corners with compressed air; 150PSI using a blow-gun.
For additional measure, I used some pseudo-stiff telephone wire to snake-out all four lines.
Also ran a bunch of silicon lubricant down the lines. (will be pouring some lubricant in the trough from time-to-time)

I can hear @M-Sport fan talk'n from hundreds of miles away. I'm keep'n my sun roof damnit. 😜

 

[foodtruck]

The rear passenger hose had a restriction due to partial clogging.

Iiinteresting, sounds like good idea for me to check those as a preventative measure

 

[TyphoonFiST]

Update: (the short details)
This turned out to be Sun Roof related.
The rear passenger hose had a restriction due to partial clogging.
My cell phone bore cam (https://www.amazon.com/gp/product/B071HYRPND/) spotted the clog in the rear passenger line.
View attachment 63075

More details:
A smaller bore cam would've made it farther down the line.
There was a small water pool in the spare tire well. Never found water like that, back there before. The towels I had back there are why there wasn't more.
My earlier testing weeks ago, opening the sunroof and pouring a cup of water down the trough didn't really reproduce the issue.
Water would immediately and rapidly exit from behind the bumper. I only saw water leave the trough if I poured what I thought was an excess of it. So paid the test little mind.
I could only reproduce the issue if I spent literally ten minutes watering my closed up car as if it were a lawn, while it was parked in a specific angle.

I removed the clamp altogether and will wrap the line with layers of electrical tape to prevent abrasion damage.
The debris corresponded with the location of a clamp; the only visible clamp out of all the lines that was visibly pinching the hose.
It's a surprise because the pinch was very minor.

Blew out all four corners with compressed air; 150PSI using a blow-gun.
For additional measure, I used some pseudo-stiff telephone wire to snake-out all four lines.
Also ran a bunch of silicon lubricant down the lines. (will be pouring some lubricant in the trough from time-to-time)

I can hear @M-Sport fan talk'n from hundreds of miles away. I'm keep'n my sun roof damnit. 😜

View attachment 63076

Where does the hose drain at?

 

[atlantaM3]

those exit behind the rear bumper cover in the quarter panel, the hose attached to plastic drains plugged into the sheet metal on each side.

 

[Intuit]

Where does the hose drain at?

The exit port is right below the vents behind the rear bumper on either side.
Oh that reminds me. On the driver side there was a tiny twig sitting at the bend in the exit on the driver side.
I fished that out with some needle-nose pliers back when I was taping and sealing off the grommet holes. (the clog was on the passenger side)
No clue how that stuff ended up in there since I don't leave my sunroof open and never open it with debris still on top of the car.
There did seem to be a thin layer of muddy build up... which I do know the source of. (parked under tree)
Did a little trimming; but technically it's still under the tree. (valuable as a sun shade among other things)
I know you say never park under trees lol...
I circled the line and exit port...

 

[isis]

So my 2016 has wet rear passenger footwell and the sunroof is obstructed and will tilt but won’t retract. I have the taillights out and will be sealing all that up as well as behind the bumper. I’m thinking I’ll still have to drop the headliner. I’m really reluctant to pull the whole sunroof assembly if I can avoid it. What do you guys think? Am I just going to have to commit? Also do the front seats really need to come out for that? Or is that Ford manual overkill?

 

[Intuit]

I’m thinking I’ll still have to drop the headliner.

Yes.

I’m really reluctant to pull the whole sunroof assembly if I can avoid it.

Likely will have to pull it if it's not retracting. Let us know what you find.

do the front seats really need to come out for that?

That might be for the sedan model? Absolutely not. Leave them in and just lean them all the way back. The rear seats will be folded down.

Overall it's not the stinkiest of jobs. Pay attention to the clips for the A pillar moldings and the wire harnesses; photograph before disassemble. Don't recall for sure whether you can avoid removing the seat belt buckle but IIRC you can just slide it all the way down and partially pull the molding away enough to free the liner. Make sure the moldings are properly reseated. If you leave a molding in a bad position for a significant time (days or week for example) you'll find that reseating them can be a PITA.

Remember to disconnect the hose for the rear window washer. The second time I was in there I forgot that and inadvertently pulled at least 50% of it from the delicate glue job that was holding it down. Fortunately I already had a hot glue gun and plenty of sticks to glue everything back, even better than the factory.