Wet on the passenger's side?

I tried blowing out the drain tube and was able to hear airflow inside the car. I also took off the plastic cover below windshield/wipers to see if water was sitting in the frame but there was none.

Yes the I checked the radiator and that was full

I have a 2001 Pontiac Grand Prix GTP. The engine is 3.8L V6 FI OHV. I just noticed the floor is very wet on the front passenger side of the vehicle under the mat. I looked under the car to inspect for rust or holes and did not find any. I heard that these cars sometimes have an issue with a water track where water runs off from the wipers. If clogged or rusted, this can cause water to come into the car. Can it be this or is there something else it could be?

Hello. I have investigated several possible reasons of why the water is going on the floor in the passenger side. I have took the cowl off, made sure the rubber thing on the bottom of the windshield was on correctly. Put new weatherstripping on the bottom side of the cowl. Took the glovebox out and watched the water drip onto the floor as water was being sprayed on the windshield. Watched the water pour into the car going down the road while it was raining. And I can not figure this out. It is going to ruin the floor in my car. I took the elbow off of the hose that come out of the firewall to the evaporator case to see if it was plugged. Blew air into the hose and you could hear it coming back into the car. Ran a wire into it and seems as if it's not plugged. Where is the evaporator case located? And does anyone have a solution to this?

Yes sir, the water drips onto the floor when you spray water on the windshield. The water drips on the floor when it is raining and you are driving down the road. The water will drip in when the car is just parked and it's raining. This is ridiculous.I can't seem to figure out where it's coming from. And it's driving me crazy. LOL. I don't know what to do about it. If it rains really hard. The floor will be soaked and the matt will float. Have you heard of this before? Any help will be highly appreciated! I read in another forum somewhere if the evaporator case gets clogged. Not the hose in the firewall. The actual evaporator case that this causes a problem as well. But where is it located? And when you take the glovebox out. You can see it dripping on the wires and on the flap thing that opens up when you have your blower motor on. But you cannot see all the way up in there to see actually where it's dripping from. HELP. LOL. Thank you :)

Passenger side floor wet. Comes from base of seat, not dashboard. No smell, no warning lights. Remains the same in high heat but gets worse with rain. Does not puddle but always wet. Just took it to the mechanic, who claims air conditioning pipe is not clogged.

Hey Raz, just wanted to add to this one because I just had to deal with similar issue in shop. This is a some information from another Grand Prix owner that posted this on the web, I found to be helpful:

I also had the same problem and spent over two thousand dollars before I found out what the problem was. All Pontiac Grand Prix from 1999-2009 that leak water on passenger floor is from the following: The front cowl panel, [Where windshield wipers are] has a air box inside the panel, that when built has a two piece construction that is sandwiched together at factory, and over time, summer heat, Icy winters etc, dries out and allows water to get into air box and drip out below dash on passenger side. To fix: Remove wiper arms, remove cowl screen, and you will notice a box looking square on passenger side, clean out in and around box opening top. Must be clean and dry. Next use ether urethane windshield sealant, or silicone water proof sealer. Reseal all the way around box, [Where metal body meets air box.] Make sure to re seal all the way around air box and let dry overnight. You can buy ether sealants at your local automotive parts store.

That would make sense, but it is not coming from the dash. It is coming from the seat area. The parts near the dash are the very last thing to get wet.

You might not think it is coming from the behind the dash, but try this, pull the carpet up and back starting up towards the dash and stick your hand under it. I think that you will find that the underneath is saturated with water, the carpet might not seem wet but there is about two inches of foam under the carpet that absorbs the water and it runs back and pools up in the passenger floor area.

Where might the water be coming from on drivers floor?

Definitly not coolant. Only happens when it is really pouring rain. Where and how do I check drain hose (?) On drivers side? Thanks.