Really bad driver side water leak: carpet soaked

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jyi786

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Hey all, I was turned onto this issue a few weeks ago and I've been struggling with it since. I could definitely use some suggestions here.

2012 Yukon Denali XL. I had kept noticing a spot of water on the driver's side carpet. When I was cleaning up the car, I took the mat out and found that the carpet was soaked. I mopped it up and thought it was from my shoe being wet. After a few more days, the carpet was still wet. I started doing research and found that this issue might be worse than I thought, so I started running through the complete battery of tests. Here's what I found and what I did so far.

1. First thing I suspected was the sunroof drain holes. I tested them, and they are free and clear. They drain properly down the vehicle. There are no water stains whatsoever in the interior headliner, so this leads me to believe that's not it.
2. I ordered and installed a brand new door weatherstrip. The old one was beat up pretty bad.
3. While installing the new weatherstrip, I took the time to get the carpet up and the padding. They were completely soaked, as well as the firewall. I spent the entire afternoon drying it out, made sure the new weatherstrip was installed properly, then put everything back together.
4. This was the place of interest. The kickpanel on the side of the driver's door where the fuses are located? It had clear evidence of water splashes (you could tell from the rust). The leak has to be coming from around this area. I stuck a dry piece of paper towel in this area as a test, just to see if I would get wet.
5. I tested with a bottle of water, pouring it down the side of the vehicle. Seemed to work ok, with nothing getting wet.

Forward to now. Today and for the next few days, there is a massive rain/snowstorm. It was raining overnight heavily. This morning I hop into my truck to go to work, look down, and what do you know: the damned carpet is SOAKED again.

When I get to work, I open the side driver's kickpanel; the papertowel has been completely soaked, and it is soaked inside there, as well, water getting all over the electrical connections, leaking down the cowl piece, and soaking the carpet.

This moldy carpet is the reason I got dead sick the past 2 years. I'd like to stop this water leak completely. Any ideas on what this issue might be and how I can fix it would be very helpful and appreciated.

Thanks so much everyone.
 

ivin74

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Have you checked the heater core for leaks? if you smell coolant inside the cab that your problem, but if you don't use coolant on your radiator you would not smell anything.


 
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jyi786

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Thanks for the suggestion.

It's definitely, 100% not coolant. It's straight up water (rain water, salt water from the roads).
 
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jyi786

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Please look at the attached video

Yes, I did see that online!

Mine is a 2012, but the video is for the older gen. Do you think this would apply to my 2012 as well?
 
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jyi786

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I just inspected everything I possibly could. I can't find anything leaking.

It's snowing out, and I had the truck on, so the water beaded up on the hood and the windshield, giving me a perfect opportunity to test with "free" water. I have the truck on an incline, so when I opened the hood, the beads collected and torrents of water splashed down and ran into the cowl area.

I checked the cowl access flaps, they are completely free from debris, and I watched as the water drained. I also opened the driver side kickpanel and inspected while the water gushed into the cowl; no sign of any water leaking into the interior. I pulled up the plastic cover for the hood hinge and checked that area; no sign of where water could be leaking. To be on the safe side, I also checked the grommet which contains all the harness wires going to the driver door. It's tight and sealed.

I attempted to bridge the little gap that's above the driver's door. That didn't work out too well (messy) but I did the job, I think.

I pulled back the carpet and inspected all the areas. No sign of water anywhere from the grommets, except water seeping from the spongy firewall. This might be leftover from what I did on the weekend trying to fix it.

I fear that this may be a sunroof line leak or most likely a windshield leak. Reason why I think it's the latter is that if it were a sunroof line leak, the headliner would get discolored from water.
 

02Lightning

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I am having the same problem but not as bad. My pad at the firewall is dry, just getting water on the floor. I was thinking of taking the A-pillar cover off and spraying the vehicle down with water and watching that area.
 

bryank97

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Has your truck ever had the windshield replaced? Look for the GM logo on the passenger side. I had the same issue on the passenger side floorboard, pulled everything out and i pulled the headliner down, you could see daylight through the 1/16th inch gap probably 2 inches long they didn't seal very well.

Also the headliner has a hard coating on the back side, so if water gets on the headliner from the roof, it may not show through.
 

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