Water on driver's side floorboard

[Sparky]

The TB is parked outside and when I opened the door I found a lot of water on top of my generic rubber floor mat and water soaked into the carpet underneath it, mostly in the corner near the fake pedal. There is no water higher up on the mat, no sign of water under/behind the dash that I could see, or around the door seals, no wet spots on the head liner to indicate a leak up there.

I know water intrusion can be tricky to find when it runs behind pillars and under carpets, but what confuses me is how my mat was half full of water. How did it get there?

I do have a sunroof (which is no longer functional) and there is a drain hose that goes down that A pillar, but I don't see how the water would get onto the mat from that pillar without a nice wet trail leading down onto it. It was rainy all night last night and most of today so nothing has really had much of a chance to dry out.

Part of me doesn't care since the TB is rusted out, has 213k on it, and sadly at this point is just a winter beater now. But at the same time I don't want my carpets being all wet as that could get all musty and moldy.

I'm going to try pulling some trim again but any suggestions where to look? This happened once earlier this year but after I dried it out I never had any more water inside that I could find until today, so it seems a heavy rain triggers it, whatever "it" is.

 

[07TrailyLS]

I didn't read through the full post sparky so forgive me if you said this already. If you look under the truck on the drivers floor board there is a hole filled with a piece of rubber or another material I don't remember. I went through a good puddle in Texas last summer and when I got home my drivers floor was soaked. It absolutely came from that large hole
Underneath and I caulked the shit out of it, under and inside and water is no longer an issue

 

[Sparky]

The vehicle was sitting in my driveway the whole time through the rain so it hasn't been splashed upwards.

 

[Capote]

Quite peculiar Sparky; you pretty much said everything that I could think of that leads to water soaking the floorboards on our rigs. Hopefully you pinpoint the problem brother.

 

[HARDTRAILZ]

Any moisture inside the dash?

 

[Sparky]

I have not had the dash apart, but I saw none from what I could see by leaning down and shining a flashlight up under the dash. But it would seem that is the only way that water can get onto the floor mat.

It is currently 32 and freezing rain out there, and my garage has too much crap in it (still) to be able to work on it in the garage, so I can't really look at it right now.

 

[HARDTRAILZ]

Thought...could it be coming through the firewall following pedals or wiring?

 

[littleblazer]

Sometimes, when facing down hill, the envoy's cup holder will fill with water from the sun roof. Other times it drips on the drivers leg. Even if you don't use it it will randomly start doing it. I never figured it out, but it's possibly a similar issue? Strange none the less.

 

[07TrailyLS]

Water could be getting into your driver side roof rack plugs. Just a thought

 

[djthumper]

Is there water pooling on the roof? Also check under the windshield waiper cowling.

 

[Sparky]

That cowling has to come off so I can fix a plugged washer nozzle, so I'll check under there.

Water shouldn't be pooling up there as I'm parked with the nose slightly downward, but also the driver side is a bit lower than the passenger side also. Hmm.

Things to look at when it stops being so disgusting outside.

 

[Sparky]

So I took a peek last night between the rain storms and I found the culprit. Water is trickling in where the fat wire harness comes through the firewall on the driver side. It is coming between the grommet and the wires, somehow. No tears, puckers, or wrinkles in the grommet that I can see from the inside.

I had fed some wiring through that grommet 3 years ago and never had a single bit of water until this year. Not sure what has changed. I didn't pop the hood to check what the other side looks like since it was dark and still rainy, but I'll look at that at some point here soon-ish and see if I can figure out how the water is getting in there in the first place.

 

[HARDTRAILZ]

I had an odd feeling that would be it. At least its easy fix

 

[Wooluf1952]

Rubber can dry out, crack and shrink as it ages. The engine heat doesn't help any.

 

[Capote]

Glad to hear you found the culprit

 

[Sparky]

The TB is sitting in the driveway idling with the heat on full blast at the floor, driver side door hanging open, to help dry out the carpet. Don't worry I'm keeping an eye on it! I don't have any other source of heat really. I sopped up as much as I could out of the carpet with rags so just letting it dry out the rest of the way now.

I popped the hood and I see the issue. The water drips down from the cowling onto the main harness, runs down it, then right where I poked my extra wires through the rubber boot has weathered/dry rotted a bit and cracked open a bit. The water just follows that crack in, along the harness, and then runs down the inside of the grommet and onto the floorboard.

Well, until it is warm enough for me to be able to use some silicone to seal all that up I guess I'll just have to make sure I don't park it with the driver front corner angled downward. Seems if it is level or any other angle the water doesn't get on that harness (or at least not enough to actually do anything).

 

[Reprise]

Sorry to make this a zombie thread, but it appears I've got a similar situation with mine. Intermittent downpours last night; happened to go into the vehicle today just to grab something...and noticed some remnants of water on the rubber mat on the drivers' side. Felt in the front on both sides of the mat...sure enough, it was damp.

Only difference is that where I park mine (usually on the driveway, as I only have room for one vehicle in there), the front - slopes gently upward, not downward. But this gave me something to go on, as far as finding the source of my own leak. Hopefully, I find something similar.

From what I can tell, it's not leaking from the windshield, the header, or the sunroof (which I don't use / care about, anyway).

 

[Tiggerr]

I've seen somewhere in a similar thread, or maybe earlier in this very thread, something about the roof rack leaking into the drivers floor...
don't remember the particulars but it's something to check...
IIRC something about a drain tube in the A pillar or at least it ending up by the drivers kick panel or something...
Maybe it was the moonroof drain... I know I've heard of both making the floor wet inside

 

[SirRobin53]

I guess it has been too long since I have been on here. I have forgotten how to edit my post to fix misspelling. But the drivers rubber door gasket was the culprit for me. It has holes in it to let water out and they filled with debris. After cleaning it out, no more water. Hope this helps. I found this information on this site but I can't remember exactly where

http://gmtnation.com/forums/attachments/document-id_-1836449-pdf.73084/
Hope this works this is where I found it