water in pass floor

OK I got a brain buster for ya'll! My 99 Tahoe has water in the front floor. It only does it when it is sitting in the rain. If I drive it in the rain nothing and when I wash it nothing. I have replaced the windsheild and cleanned out the a/c ducts. My blower motor case will fill up with water then drain on the floor. When I turn on the blower motor it will throw the water out but not out the vents or on the floor. It dosen't have the smell of coolant or color. So where in the world is it comming from????

Heater Core??

nope not the heater core no loss of coolant in the system

chris, when the windshield was replaced, if the screws were not all put back into the black piece that covers the reveal between the windshield and the hood (cowl), the hole that the screw occupied will allow water to leak into the cab. my truck was leaking too, and that is what it turned out to be. i used a slightly bigger screw when i replaced the screw, and put some sealant over the screw head to make sure that i didn't have any more leaks. that's what it turned out to be for me, may be worth the look. pull off the black cowl cover and look and see if all the screws were in it or not, or if the screw holes are rusted a bit and may allow some water past the hole. i found a couple leaks when i changed out my carpet, just did the ol' water hose trick and kept searching until i found where the leaks were. i also had a leak on the sealant on the top of the cowl area at the rear right side of the engine compartment. factory sealant had just dried and cracked and was letting water right in. patched it with some windshield sealant, painted it white like my truck, all good. i've heard not to use silicone caulk as the acetic acid that it gives off as it cures can cause corrosion. hopefully this helps or is the solution to your problem. branndon.

It's not the windshield either. This is a very common issue with these trucks. I have never heard of a great fix yet. Mine leaked before and after the windshield was replaced. It has not been leaking much lately but it does. Some people say it is because of missing screws in the cowl...but mine are all there. Others say is is a plate under the cowl that needs to be pulled off, sealant removed and resealed.

If the rain stops by the weekend I am going to try some of the things ya'll said. I want to replace my carpet but I don't want to until the leak is stopped. I will keep ya'll updated. Thanks for the help.

Others say is is a plate under the cowl that needs to be pulled off, sealant removed and resealed.

Click to expand...

I have fixed 2 Tahoes by removing the plastic cowl and then removing the metal plate that is secured with seam sealer and the actual leak is from the seal where the heater box mounts up to the cowl for the fresh air to come in.

^^^yup, that's what I'm talking about

what type of sealer do you use??

I fixed mine for good...traded it in.

lol I love my hoe way too much for that!!

I fixed mine and them got rid of it later.

I just used DAP outdoor window/door caulk but I had never heard about the acid causing corrosion.

I have the same 'wet carpet syndrome'. Anyone willing to do a quick 'how to' with pics on the panel removal part, i can do the caulking if i can get to the cold air intake of the air box.
Thx in advance.
PS: Thanks to the folks who contributed to this thread, it does help.

just cause the screws are all there doesn't mean that it's not leaking around the screws. i was in the middle of a carpet change/sound deadening job when i found the leak. i put some of the windshield sealant (3M) over the screw hole, ran a larger screw down into the hole, put some more sealant over the screw head, and then put a small patch of some sound deadener over the top of all of it. hell or be damned if it'll leak again. lol. anyhow, it's not a big job, there's a screw at each end of the black vented cowl section, and another 2 or 3 screws in the middle. it's a 3-section cowl cover. the ends hold down the middle section. and i think there's a little tab you can lift up on the wiper arms that allow the arms to pull off of the studs. probably take all of an hour for someone that's not too mechanically savvy, less if you're handy with tools.

My leak was defintely not from the screws it was the seal around the fresh air intake.

I think we may just get a break in the rain long enough to try this out this weekend. So if I do get the chance I will take some pics along the way.

I pulled off the cowl today and all of my screws were very loose. So I sealed all of the screws with some waterproof caulk. Now I have to wait for the rain to see if it is going to work or if I need to caulk the plate or not.

I had the same problem. I replaced the screws that were left out after having a windshield replaced. I seled them good and it doesn't leak now. I have another leak on the drivers side. Any ideas?

bass, my truck had a leak on the driver side too, turned out to be the sealant from the factory that had dried and cracked. up on top of the cowl, in the corner where the base of the windshield/cowl/firewall meets. next to the drivers side hood hinge attatchment. i know it's a pain, but pulling your carpet back and running some water over various places until it starts coming into the cab is probably the best way. i fought the same battles a while back when i replaced my carpet. found a couple leaks i didn't know i had.

Thanks branndon_b. I'll check that out.