Thread: Tell me if you've heard this one before: Water in passenger footwell!

So it's been raining here, and my 2001 GT has water in the passenger floor footwell.
Ordinarily, I'd pull off the hood cowling and get one of those plastic shields for $14 on Amazon and install that. . .
. . . except I DID THAT THIS SUMMER. So I don't expect the water to be coming from there.

I also had the entire interior and carpet out of the car to replace it this summer, and there weren't any obvious holes or anything, and there isn't a spot of rust anywhere on the car.

So. . . Ideas for troubleshooting this?

2001 Grand Prix GT sedan. Yes, it has a sunroof.

Originally Posted by Slick2500

You do realize that part is $5 from a GM dealer right?

I'd imagine it should probably go without saying that "no", I didn't know that. But for anyone who wants to get one, it's useful to mention here, so. . . there's that.
Right now, Amazon lists it for $6.89 and free shipping, but when I bought it this summer it was $13.56. And for a different perspective, it can be easier to spend 60 seconds or so ordering it online at Amazon during the week when I have to work and don't have time to work on the car anyway and have the thing show up before the weekend when I *can* work on the car, than taking time off work during the week when the parts department is open and driving 20 minutes to my dealer to get it and then drive another 20 minutes back home, and that's if I'm lucky and there's no traffic gridlock.

Anyway, I'm planning to wire up a carbon fiber aftermarket seat heater to the passenger seat, so I'll need to pull the seats to tap into the driver's seat heater wiring, and that seems like it will be a good time to peel back the carpet and run the hose to see if I can find a leak. I was just hoping someone had knowledge of other potential leak sources beyond the well-known hood cowling route through the blower fan housing.

Originally Posted by idrivejunk

Water in floor can also come from a detached weather liner on the door. It is attached with butyl rubber and water can come from behind the door trim panel and over the sill trim panel.

I'm leaning towards a clogged AC drain. When I re-did the entire interior on this car over the summer I had all the door panels off so I could restore everything, and the door shields are all together like new, and the door weatherstrip seals are all in great shape. I even replaced the weatherstrip on the driver's door because it had a couple tears in it. I'll check the AC drain today.

And the verdict is. . . AC drain duct.
I accessed it from the open hood. Can't even see the thing, only found it by feel.
I took out the coolant overflow tank (used it as an excuse to give the exterior of that a good cleaning) to make it easier to reach, but still had to find it by feel; couldn't see it at all. But there are pictures of it in other threads and other sites, so I knew where to reach for it. It was a few inches further down (towards the ground) than I was expecting, but the general description of "on the firewall behind spark plug #4" gets you right in the neighborhood. Pulled the drain elbow off, and the oft-described waterfall of water poured out. The rubber elbow was completely plugged with crud. Gave it a good washing and trimmed the rubber away from the outlet to make the outlet bigger. Shoved a soda straw back up into the AC box and poked it around, but didn't encounter any other crud or water. Replaced the elbow, replaced the coolant tank. Bonus: Discovered the shop that recently replaced my power steering pump didn't even bother to tighten down my strut tower bar. The bolts were just hand-threaded in a few turns. I torqued them back to spec for the aluminum brackets.

I used a hand-cleaning attachment on my Bissel Big Green carpet machine to suck out as much water as I could from the footwell and the floor mat and left the floor mat out in the sun to dry out.

In more hindsight, that explained a number of things I'd noticed.
-Every time I started the car with the blower fan and some selection of air/defog, the first puff of air onto the windshield would leave a thin layer of fog that rapidly evaporated off in a few seconds. I believe that was the water in the AC box blowing moist air in the top of the box onto the windshield.
-I heard some sloshing noises, which I attributed to the cooling system not being properly bled of air after the water pump was replaced, and even took it back to have it bled again. In hindsight that was probably water sloshing around in the AC box.
-Finally, with the AC blower on if I took a hard right turn there was a noise that sounded like plastic scraping coming from the blower. That was probably water sloshing into the blower fan compartment before it made its way down to the passenger floor carpet.

So. . . yet again, taking all the symptoms together, this makes sense. In another thread I explained that I owned this car from 2003 to 2010, when I sold it to a neighbor, and she gave it back to me this summer. She had complained of water in the passenger footwell, and when I took the cowling off I found the cowling weatherstrip *in* the blower fan box, so I figured installing the splash shield and a cabin air filter had cured that problem. No doubt that was one cause of water intrusion, but I clearly had (at least) two, which is why the "water on the carpet" problem can be tricky. I'll check those sunroof drains, too.

I know nobody replied to this for a few months, but I do appreciate you writing down what you did. So many forums end with "I'll try that later and report back" so I had to mention something. Thank you for following up.
I replaced my heater core last week and the cowl thing 2 months ago and I still have the water leaking. Gonna go dig around for the drain plug this afternoon (I'm not gonna report back though ).
Thanks!