Water filling driver side floor pan.

The wife's 2008 Prius has apparently been collecting water on the driver side (front and back) floors for some time. Allegedly, it doesn't have to be raining, or even wet outdoors at all for it to accumulate. The fluid is NOT engine coolant or windshield washer fluid; clear, colorless, and tasteless (yeah, I did taste it) liquid, totally saturating, and partially filling the floor pans on the left side, while leaving the area directly under the driver seat dry. There seems to be some dampness on the passenger rear carpet, but it's nothing like the driver's side. The undercarriage has plastic shielding of some sort covering the areas of the floor where the water has built up, so I can't immediately see any drain plugs, or holes where water my be coming in. Before I start tearing things apart, I thought I would run the strange problems through the forum, and see what you all might come up with. I've seen some reports of possible A/C drain issues in the passenger front floor, but this is definitely left side. Oh, yeah....there's a stink along with it, but I'm assuming that may be mold caused by the standing water, or something totally unrelated; but I thought it bore mentioning. Thanks.

 

You should see me when I shave my head and trim to a goatee. If I grimace a little, the likeness is even greater. I've thought about doing him for Halloween.

 

She hasn't been using the A-C, and carpet directly under dash is not damp. Anyway, I vacuumed at least a gallon of water from the floor pans yesterday, and there was no rain. I'm talking an inch of standing water, driver's side, front and back, with accumulation also on right side rear....just not as much. She said there was more water after work than there was when she drove there. Can't see the floor from under the car. There is some sort of plastic sheeting bolted on the undercarriage. Tomorrow, rear seat coming out and gutting the hatch space to see what I can see. And also, blow out the a-c drain just for chuckles.

 

Sure is a lot of water. I think she took pictures. If I find some I'll post them. I almost shit when I opened the vac and saw how deep it was. Furthermore, the padding under the carpets was still totally saturated. If I wanted to spend 45 minutes sucking at the floor, I probably would have pulled out another gallon. Damn.

 

Who wanted a picture? This was taken early Friday night, after a day without rain! The car was parked at her job for the day, and when she drove it home, this is what the right rear floor looked like.

 

Here's an update. Someone earlier suggested I check the spare tire well for water build up. I secretly thought he was nuts (sorry), but I figured I would check every lead. Guess what...it was flooded to capacity back there. So I tore everything out to try to find out why it was full of water (after sucking it out with the wet-vac), and to figure out how it was also filling the floor pans. Pulling out the rear seat first, I found water soaked into the bottom of the padding; easily 8 or ten inches higher than floor level. I ripped out all the trim and found water at an even higher level....up in the quarter panels. So, I took to the hose, and started soaking the car on the outside, while all the trim was removed. Here's what I think was going on based on water leak test performed. Refer to photo: there are two grommets, for wires (et al) to pass to the hatch, at the top of the rear deck frame (in red). Water is apparently getting in through them (they are loose fitting, man), channelling down through the frame rails (path in yellow) and literally raining down behind the trim panels, collecting in the wheel well (blue). When enough water had built up around the tire over a long period (she didn't even remember there was a spare in there), it overflowed. With no other place to go, it started running under the rear seat (soaking the padding) toward the front of the car, and spilling over into the floor pans. That's where it sat, soaking into the padding. When utterly saturated, the level on the floor finally got high enough for her to notice pools. What a trip. There is no leak in the front of the car anywhere. All the water came from the damned trunk. SOB. Now; I have to figure out how to fix it. Maybe simple gasket sealer. I tell ya'.....this one was baffling, but I'm fairly certain I solved the mystery.

 

We did the water spray test. When water was directed at the grommets, it started raining inside the car. All the weatherstripping and body seams are solid....no cracks or splits of any kind. And the grommets are so loose that when I gave one a wiggle it popped out of its hole. I thought I broke it, but it dropped right back it. It's just loose. The bolt holes that hold on the rear hatch pistons are also suspect, but it's impossible to hose down one of these areas without soaking the other. Oh, yeah...I sucked all the water out of the battery tray too.

 

I checked out that other thread, and went back to check mine according to this picture he posted. On both sides of the roof, there is a black rubber strip that run from front to back. At the rear most point, where this rubber clips on, there is an observable, hairline crack - so fine I missed it the first time I checked. Mine are not so obvious as the one in the attached photo, but I can see them. Black RTV to the rescue tomorrow. Fill those cracks up, and glue down the grommets. Thanks for that tip.

 

I deduced that the spare tire well had been finally filled (after who knows how long accumulating water) the day before, when we had a lot of rain. While driving to work, the water in the now totally full trunk sloshed around....while turning corners, over bumps and at stops lights. It just spilled over the brim and ran "downstream"; the only place it could go was into the floor pans. If you could see the car disassembled, my explanation wouldn't sound as wacky as it must in this writing. With the hose running, we could actually follow the water trail, and the theory just wrote itself. What a tough nut the was, I tell ya.