Wet Passenger Floorboards - Hopefully fixed

[Awfiretto]

Hi all,

I know there’s some old threads about this, but I figured I would post my findings and attempt to fix in hopes to save people reading 19 different things to arrive where I did.

Everything was grand, then when vacuuming after a car wash, after a Texas Downpour, I noticed the carpet wet...

I removed the cowl
(wipers were a pain - tip - hit the nuts with WD40, let sit, and wiggle back and forth, they will come off, just keep trying) - also be careful of the wiper washer hoses, one got disconnected. I did not remove the cowl entirely, I just let it rest on the windshield, did not want to fuss with the hoses for the washers.

I noticed the cover, over the HVAC intake had gunk around the seal. I cleaned then siliconed over it.... then, after doing that [emoji849], I was googling to make sure I fixed it... I realized it could have been a multitude of things :

HVAC Intake seal
Gunk in the weather stripping (top of door)
Sunroof drain clogged
Cowl drains clogged causing flooding into the intake.

Turns out as I inspect each item- they were all probable causes, except the cowl drains being clogged.

I undid my silicone seal on the cover plate to get under the cowl and ***** the intake. The seals also had the same wet gunk look.

Then proceeded to clean out a little junk. Then bought a whole tube and went crazy with it to seal it all up around the outside of the seal for the intake. Apparently this is common in many other make of vehicles 10+ years old, Texas heat and rain type thing.

Then proceeded to check my weatherstripping around the doors and windshield... disgusting... there is no way water was evacuating right with all that gunk 27 towels later... they are clean.

Then I checked the sunroof drains, sure enough the passenger side was clogged. Pulled the tube and used my lungs to blow out a bunch of crap.. sprayed cleaner down it... repeat.

There’s no doubt in my mind all of these played a part, and least one was the primary cause for the leak... but it should be water tight now. I have no idea why the passenger side was so bad, I checked the driver and it was much cleaner!?!?!?! Maybe it was parked consistently next to a dirt factory on the passenger side.

I also bought a huge “damp rid” bucket from Walmart when getting the silicone. Sat it under the foam and carpet to dry things out, and I’ll be dammed.... while I was fixing the outside stuff it dried almost all moisture. I’ll leave it in the truck until it starts filling up, if it does...

Either way, as some of you know I’ve been through a crap load with this 104k mike 07 LT. I do pray it stays reliable, and feel good knowing I have caught up on all the maintenance with it.

Question, why does the vent stay OPEN when the truck is off, I don’t get it!

Here’s a before and after, my hands are big and I did this in a hotel parking lot as I’m on the road right now, it’s the not the prettiest... just call me “Picasso”


Sent from my iPhone using Tapatalk

 

[kbuskill]

Question, why does the vent stay OPEN when the truck is off, I don’t get it!

Because evidently your truck had the update at some point.

I don't have the TSB info in front of me at the moment but as best my memory serves...

GM kept getting complaints of a musty smell from the A/C vents so they issued a technical service bulletin to reprogram the A/C control module to open the vent to allow fresh air into the evaporator box to dey up the left over condensation.

If you notice you can set the A/C control to recirculate and shut the truck off and when you turn the truck back on it will be back to fresh/outside air mode.

They also reprogrammed some trucks to turn the A/C blower motor on if certain conditions were met to again help dry up the condensation that was left over. This feature was called "Afterblow". Check it out here... https://www.tahoeyukonforum.com/threads/afterblow.96895/

Thanks to James, @swathdiver

My personal opinion is that GM must have screwed the pooch when they designed the drain for the evaporator air box. If the drain was at the lowest point then there shouldn't be any way for it to retain water. This is just a guess on my part though as I have never had the evaporator box out on a GMT900.

 

[Awfiretto]

@kbuskill @swathdiver .... mind blown!



Thanks for that info... good to know I’m not crazy for asking. It’s looking like I need a tech 2... one day I’ll spring for one.


The leaks were much better. But I definitely had the weatherstripping leak found in other search’s. Ended up going crazy with silicon after cleaning to stop it again. Had to go through the car wash a few times with everything apart to make sure I stopped it.


Also siliconed the sunroof drain at both ends. Just to make sure.


Funny thing... my ONSTAR light is now permanently green so far. I tried everything but the VCIM and antenna cable to fix it... then just let be due to other issues. Either the water got dried up from the damprid, or I wiggled the cable enough to solve it. Who knows. Happy to see green.


In some respects, a vehicle lasting 15 years or more with 200k + miles.... I’m sure there’s some long term stuff that GM had difficulty seeing. On the other. There is basics... like a freaking cabin air filter... or weather stripping.... that cause me to shake my head.


It’s a great truck in so many ways though, like a fiery relationship, pissed off one moment. Then all back in Love once it’s “fixed”.