Why is my floorboard so wet?

I have a 2000 Altima. Lately (this past week, I think) I’ve been noticing the floorboard on the passenger side was damp, then progressively wetter. I looked under the mat today and it was puddled with water.
When I went around a curve and slightly uphill, I heard water trickling and sure enough, it’s coming from the inner part of the foot area–if you were a passenger and stuck your foot up kind of under the dashboard/console (beneath the glovebox), that’s where it appears to be coming from.
I assumed at first it was just condensation from the air conditioner, but it’s a lot of water, and I’ve never noticed this problem before. It does appear to be water, not coolant or anything chemical, at least according to the smell/feel of it.
Any ideas about what it might be or how to fix it?

My vote – a plugged drain in the air conditioning system.

If you haven’t been running the air conditioner, then you’ve got a leak somewhere.

Third and last guess, last time you went running, you stuck your water bottle under the passenger seat and forgot about it.

But plugged air conditioner drain is most likely.

Do you have a sun roof? Once I had a sun roof that was just slightly “off.” Water could get in, but only if I was parked at an angle in a certain way. It took me a while to figure out where the water was coming from because the problem was so intermittent, I didn’t suspect the sun roof at first.

Nope, no sun roof.
I suspected something to do with the air conditioner but I didn’t have the vocabulary to express it. I’m guessing Finagle may have it, but I need to check the link to get more info still.

Finagle got it in one. AC is a dehumidifying process. The water it removes is supposed to drain outside under the car but drains do get plugged.
Get this taken care of ASAP. Wet floors can lead to mold, mildew, and rusted out floorboards.
None of these are considered a good thing.

Or you could just drill a hole in the passenger floor and let the water drain out there.

And you could give a guy with compound fracture a band aid.
Neither of these suggestions is a good idea.

I agree, but when I was a kid, we had a Valiant that had this problem, and my Dad, never one to spend money recklessly, had me drill a hole in the floor, and tape a funnel to the evaporator, with a hose leading the hole in the floor. We drove that car for years that way…

What I usually go to unclog the A/C drain is to jack the car up and blow compressed air in the drain.

A long wire might work too.

My wife had to have her car’s AC serviced a month or so back and they apparently didn’t put everything back together, because three days later we noticed a good amount of water on the passenger’s side. We vacuumed it out with the shop vac and managed to suck up almost a gallon of water.

So, yeah, I’d say there’s something wrong with your AC.

I would prefer cleaning it out manually rather than blow crap up into the case where it will eventually settle and replug the drain.

Back to the sunroof suggestion…many have drains around the perimeter. They can get clogged with debris (dirt/leaves, etc.) and need to be cleaned out lest the water run down the “A” pillar back behind the dash. Suggest seaching for a discussion forum for your vehicle. Betcha you’ll get some more specific info.

Superb advice in general, but the OP mentioned in post #4 that she had no sunroof.

I’m surprised no one has mentioned that it could possibly be a heater core leak. Do you ever smell antifreeze? Do you ever see fogged windows (or steamed windows) on the inside?


I have had this problem. It’s your AC and it’s a pain to try to repair yourself. Take it to a mechanic. Also, make sure that your floor is thoroughly dried out because this is a great way for rust to start eating through your car.

Yeah, but one of them was funny-- most likely, intentionally so.

I removed the carpet from my Jeep and took out the drain plugs so water wouldn’t collect when it rains with the top down. But, of course, it was meant for that. An Altima with no carpets and a hole in the floor would be a bit strange.

I’m thinking it’s definitely the AC drain. There no smell of antifreeze and the fluids levels are all good.
We took it apart this morning but didn’t try to clean it out (after reading the website Finagle linked) and it’s now back together, so I guess I’ll have to call a mechanic. Hopefully my Car Guy will fix it for cheap.
Thanks for all the info!