Passenger Floorboard is always damp

[tutonetahoe99]

This is something that has been driving me insane! I own a 1999 chevy tahoe, and it has had this issue for awhile now, with the passenger side floorboard carpet being wet most every time I check it. I have put alot of silicon sealant on the windshield cowl screw holes that lead to the hvac vents in the cabin, and it is still wet when. I have also had the ac evaporator drain checked, and unclogged and it is still damp on the carpet. I know that it isnt coolant because I've replaced the heater core before, and I can see little drips of water on floor pans when I pull the carpet up. This has been a very frustrating ordeal, and I have a feeling that sooner or later I am going to have to replace my floorpan, and carpet. Any advice or help would be greatly appreciated.

 

[Caman96]

Search in this forum for causes. There’s some good threads on this. Been there…

 

[GrimsterGMC]

This is something that has been driving me insane! I own a 1999 chevy tahoe, and it has had this issue for awhile now, with the passenger side floorboard carpet being wet most every time I check it. I have put alot of silicon sealant on the windshield cowl screw holes that lead to the hvac vents in the cabin, and it is still wet when. I have also had the ac evaporator drain checked, and unclogged and it is still damp on the carpet. I know that it isnt coolant because I've replaced the heater core before, and I can see little drips of water on floor pans when I pull the carpet up. This has been a very frustrating ordeal, and I have a feeling that sooner or later I am going to have to replace my floorpan, and carpet. Any advice or help would be greatly appreciated.

I don't suppose there are any holes drilled in the lower firewall or floorpan that would catch spray off your front tire when driving and soak through to the carpet inside?

 

[Caman96]

Dreaded passengers side water leak.

I have been putting this off for a long time. Well today was the day. I looked at a bunch of youtube vids. Several years ago, my windshield was leaking and it was on the passengers floor, but some flowable silicone, and that issue was solved. So in time, the leak returned, but I could tell it...

www.gmt400.com

Water leak

I have been chasing a water leak on passenger side into the floorboard of my '97 for years. Shop thought -resealed. Thought windshield gasket replaced. You can run the hose all day long onroof,fender, cowl and it never leaks. I got in it during one of our rain storms and saw it weeping through...

www.gmt400.com

 

[tutonetahoe99]

Thanks for the advice, I have put off solving this issue for too long. Im gonna try running a hose all along the windshield and seeing if it leaks and go from there.

 

[Caman96]

Not sure if you read my resolution, but whatever is causing yours, cleaning out the drains is something that should be done anyway.

 

[HotWheelsBurban]

This is something that has been driving me insane! I own a 1999 chevy tahoe, and it has had this issue for awhile now, with the passenger side floorboard carpet being wet most every time I check it. I have put alot of silicon sealant on the windshield cowl screw holes that lead to the hvac vents in the cabin, and it is still wet when. I have also had the ac evaporator drain checked, and unclogged and it is still damp on the carpet. I know that it isnt coolant because I've replaced the heater core before, and I can see little drips of water on floor pans when I pull the carpet up. This has been a very frustrating ordeal, and I have a feeling that sooner or later I am going to have to replace my floorpan, and carpet. Any advice or help would be greatly appreciated.

There's a little rubber elbow that is part of the air box drain. If this is not in place, at the base of the firewall on the passenger side, it will drip on the floorboard. Had this happen to my Burb.

 

[Caman96]

There's a little rubber elbow that is part of the air box drain. If this is not in place, at the base of the firewall on the passenger side, it will drip on the floorboard. Had this happen to my Burb.

…and another reason^^^. Can be a PIA to find the culprit, took me about a month.

 

[Scooterwrench]

I've been fighting this problem since I bought ol Smoky. It had a crack running all the way down the center of the windshield so I had Safelite install a new one last week in hopes it would fix the leak too. I was there watching the guy and got to check out the condition of the pinch weld around the windshield frame. Even the installer stated that it was in great condition. I watched him install the windshield and thought he did an excellent job. But nope still leaking! I was going to call Safelite but figured I'd better check before I tore 'em a new one. I had my brother run a water hose across vent grill and water started pouring in. I wound up removing the vent grill,hood,glovebox liner,ECM,parking brake,both front speakers and pushed the fuse box out of the way for a better view of where the leaks were coming from. I think I have the left side fixed,it was way up in the top left corner where the vent cowl,firewall and inner sidewall met. There is no rust up in that corner. I think a chunk of the seam sealer had fallen out and left a hole big enough that light came through. I caulked it with ultra grey sillycone and the other seam that runs down through there. I'll leak test it in the morning and move to the right side. The right side is going to be a little tougher to do.

Check your vent cowl!!!

 

[Caman96]

I've been fighting this problem since I bought ol Smoky. It had a crack running all the way down the center of the windshield so I had Safelite install a new one last week in hopes it would fix the leak too. I was there watching the guy and got to check out the condition of the pinch weld around the windshield frame. Even the installer stated that it was in great condition. I watched him install the windshield and thought he did an excellent job. But nope still leaking! I was going to call Safelite but figured I'd better check before I tore 'em a new one. I had my brother run a water hose across vent grill and water started pouring in. I wound up removing the vent grill,hood,glovebox liner,ECM,parking brake,both front speakers and pushing the fuse box out of the way for a better view of where the leaks were coming from. I think I have the left side fixed,it was way up in the top left corner where the vent cowl,firewall and inner sidewall met. There is no rust up in that corner. I think a chunk of the seam sealer had fallen out and left a hole big enough that light came through. I caulked it with ultra grey sillycone and the other seam that runs down through there. I'll leak test it in the morning and and move to the right side. The right side is going to be a little tougher to do.

Check your vent cowl!!!

My driver side drain was plugged, so when either a downpour, carwash or hose would fill up the under the cowl, passenger drain couldn’t drain it fast enough and would spill over into blower then onto floor. Check those drains and the famous screw holes.