Strange wet spot in carpet

[ukrkoz]

07 Tahoe LT

I have strange wet spot on the driver side, in the carpet and padding, right where my right heel rests driving.
Spot is about 4-5 inch diameter, pretty circular.
NOTHING to the sides of it is wet. Carpet on the driveshaft well, firewall side, all is dry.
OEM floor mat has no holes in it, to assume, that water drips off my shoe and through it.
I had windshield replaced in March. Installer, bless his heart, replaced it again a week ago.
I had carpet dried out like desert, with portable heat fan.
Spot is back.
There is no floor plugs, best I can tell, there.
Any ideas? Drain plugs for AC are nowhere close. Is there heater core drain that could cause that? Truck does slowly take coolant. Slowly. I add maybe a cup in 2 000 miles. Engine had heads done. I added UV dye to coolant few months ago and could not find ANY leaks anywhere.
What trips me is that everything around that wet spot is bone dry.

 

[Joseph Garcia]

Did you check immediately above the wet spot under the dash and see if something is wet above and is dripping directly downward onto that wet spot?

 

[ukrkoz]

Just did. UV light included. Nothing. All dry. NO signs of any water or similar. And, far I know, there is no water lines above the gas pedal in the dash. Heater core is off to the right of the driveshaft well. Spot is centered about 4 inches towards the rear off the gas pedal lower edge.
1st windshield replacement was done by one of the techs that work for the guy, who did about 5 of our windshields by now. Superb job every time. He warranted it and replaced it himself. And that AFTER he was here 2 weeks ago, stripped everything around windshield and checked everything, headliner included. Nothing. Man spent a good 1.5 hour looking for any signs of leaks. He even sealed those clips for molding in pillar A, as he saw them leak water inside on some cars.
I safely bet, windshield is not the case. Unless there is crack somewhere weird. But truck was not in any accidents. Just age and miles.

 

[ukrkoz]

Any chances, moonroof can do this? But, then again, headliner is dry and clean. And, anything to the sides and up from the spot is dry. It's like as if it's leaking from the bottom UP. Floor plugs normally do this but there are none there.

 

[Bill 1960]

Just leave a balled up towel above the wet spot to confirm it comes from above. Then you can relocate a dry paper towel or tissue to chase it upward to the source.

Or it will tell you it coming up from below.

Liquid leaks do many odd things and can travel horizontally on seams, cables, all sorts of channels.

 

[5StarG3neral]

Following this because I have the exact same issue with my '13 Yuk

 

[ukrkoz]

Just leave a balled up towel above the wet spot to confirm it comes from above. Then you can relocate a dry paper towel or tissue to chase it upward to the source.

Or it will tell you it coming up from below.

Liquid leaks do many odd things and can travel horizontally on seams, cables, all sorts of channels.

Balled towel? But I do like paper towel sheet idea. Of course, no rain today but it is supposed to rain next few days. Indeed, if I spread paper sheet on the floor, it should show if it drips down from above. I'll also stick some onto firewall and under the carpet, towards the driveshaft well.
Thank you

 

[Rocket Man]

Water can also run down from the firewall and pool in a horizontal area without leaving a trace on the firewall or the jute.

 

[avalonandl]

Possib;e windshield leak?

 

[Rocket Man]

Possib;e windshield leak?

Read post #3.

 

[avalonandl]

Post is too long.,.. LOL

 

[Rocket Man]

Post is too long.,.. LOL

Haha, yeah it’s all of 12 posts!

 

[adventurenali92]

I’d be willing to be bet either your sunroof drain is not connected properly and it’s running down the a pillar and pooling in the drivers footwell area. Or the onstar shark fin antenna above the drivers seat has a bad gasket seal in between the antenna base and the roof, it and it’s following the same path down the a pillar.

 

[Alexquade]

I had like 5 cracks in the body seam sealant stuff on the outside at the firewall. Body shop took the front fender off and resealed it! It was an 11 and water was puddling right there then got the point it was constantly holding water.

 

[V327839]

Do you have hydro boost brakes? Wet floor near pedals can be power steering fluid leaking from brake pedal lever down firewall. Just an idea.

 

[EvergreenZ71]

I’d be willing to be bet either your sunroof drain is not connected properly and it’s running down the a pillar and pooling in the drivers footwell area. Or the onstar shark fin antenna above the drivers seat has a bad gasket seal in between the antenna base and the roof, it and it’s following the same path down the a pillar.

If it has a sunroof I agree that should be the first place to check but I’d start with having it checked to see if it is simply clogged. My old 02 Tahoe would drop from the roof center console into the cup holder.

 

[denalianyone]

I had like 5 cracks in the body seam sealant stuff on the outside at the firewall. Body shop took the front fender off and resealed it! It was an 11 and water was puddling right there then got the point it was constantly holding water.View attachment 358847View attachment 358848

Where is this located?

 

[calsdad]

I had a problem with water building up in the footwell of my 2003 Suburban when I had it (it ended up being one of the reasons I got rid of it) At first I thought it was from snow being tracked into the truck during winter - because that seemed to be the connection. But then it started happening during the warm months. Truck did not have a sunroof - so it wasn't that. The closest I got to diagnosing it was that it seemed to coming from the firewall or rain gutter area below the windshield. Tried to flood the area a few times with a hose to see if I could catch the leak - but nothing. The worst part was - it didn't seem to happen all the time.

There was another bad side effect though from the water gettting in: it kept corroding the air bag module under the front seat. You would think "how the hell would this happen?" as the module is located above the footwell level. I had the module replaced once at a shop - to the tune of something like $700. I just sort of shrugged that off - as the snow getting inside the truck and under the seat or something.

Then it happened again a couple of years later. This time I was like "WTF". Turned out - the culprit seemed to be that the rug underlayment - that brownish jute or whatever they call it - was acting like big sponge and sucking up the water that was getting into the footwell. Then it just migrated the water up to under the seat - and because the rug and underlayment went OVER the module - the module was just sitting there in a saturated wet environment - like all the time. Eventually it got into the connector and corroded the whole thing to the point where the module malfunctioned.

So the second time I replaced the module myelf and cut away all the rug and underlayment from around the module so it wouldn't be covered over any more.

Given that experience - if you're getting a wet spot in that footwell - I would check carefully just how far the moisture is migrating under the rugs. You might be surprised how far it's going.

 

[ukrkoz]

Ok, apparently, replacing the windshield by the person who knows, what he's doing, fixed it. Truck been outside through showers and now days of snow.

 

[Rocket Man]

Ok, apparently, replacing the windshield by the person who knows, what he's doing, fixed it. Truck been outside through showers and now days of snow.

I thought after the first replacement he stripped everything and water tested for 1 1/2 hours? So that guy not only failed at replacing the windshield but he also failed at water testing? WTF?