My $0.02 on wet driver side floor boards

Before I start, I just want to say thanks to everyone for the all the help reading this forum has given me.

I have been fighting a driver side wet floor board issue in my 2000 GTZ for more than a year. I never noticed any wetness during the dry hot part of the summer while the air conditioning is being used all the time. But during the rainy part of the year, I could have as much as an inch of water. From this I drew the conclusion; the problem was not with the ac evaporator drain. As part of the diagnosis, I noticed some wetness on the left side of the car, just in front of the drivers door. I had put a battery wire for the amps in the trunk that entered the inside of the car near that location, so I thought I had not sealed it up very well. I removed the fender and used some Rust-oleum LeakSeal, an aerosol rubber sealer. It really makes a mess but does a good job sealing things. But that did not fix the problem. I decided to take the fender off again and noticed the drain for the sun roof was not installed correctly.

https://www.dropbox.com/s/bqrqqjpr4x..._1292.JPG?dl=0

Easy enough to fix.

https://www.dropbox.com/s/8a11f79td9..._1297.JPG?dl=0

The wetness on the right side was fixed, but there was still more water coming in. To search where the rest of the water was coming in, I removed the carpet. I am going to replace it anyway. That is when I found the leak at the ac evaporator drain. I am sure there are some decent pictures someplace in this forum for this type of fix, but here is the ones I took. Hope they help.

https://www.dropbox.com/s/igtweaqnjn...12.07.jpg?dl=0

It is a lot further down on the firewall than I thought it would be. Whoever said this is a PITA to work on was not wrong. I tried to use some 3M Windo Weld. But I found it stuck to my hands better than it stuck to the car. Every time I removed my hand, the weld came with it. I decided to switch to some silicone sealer. While smearing this sealer, you cannot see where it is going as you hand is in the way. I put as much as I could trying to make sure I got everything covered.

https://www.dropbox.com/s/fajfz1jq01...52.32.jpg?dl=0

I used a coat hanger with about a half inch on the end bent at 90 degrees to clean any of the silicone that went into the drain. I hope this now fixes my problem. If I can get the can close enough, I will also spray on some of the Rust-oleum sealer.

I will try a car wash soon to see in any water comes in and report the results.

it could also be a rusting pinch weld behind the windshield. you can take your a pillar trim off and spray some soapy water on the outside along the windshield and use compressed air to blow inside the car. if it bubbles on the outside youll find your leak.

usually if it were a clogged evap drain hose the pass side would flood though. just a heads up with that too.

I took my car to the car wash and run it through, no water leaked inside. After a few days of driving with the AC on, also no water leaked inside.

I call this a success. But the final test will be a hard rain fall. But here is nothing scheduled in central Texas for the next couple of weeks.

Time to start the clean up and rebuild of the interior.

This is how I fixed it. I got a shop vacation, a plastic funnel and some pvc tube that can fit on the funnel. Hook hose to vac, funnel large side to hose, and plastic tube over small part of funnel. You have to do what u can take dash and get to the drain area from passenger side. Use the tube to vacuum any debris from in there. Gers in from the cowl and ac system. Once that us clean replace all parts as you took them out. Lastly get and old cooler hose somethings with a 90 degree bend that will fit and attach it to the the drain hose from that drain where you found the leak. The opening is on the firewall in the engine bay around the rear engine mount. Angle the rubber bend down. I did this as added me sure to make sure wind speed was not pushing droplets back into the drain. Haven't had the problem since.

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Thanks to everyone for their ideas. It is not the AC water leaking back into the interior. I have been driving the car all summer with the AC blasting and it has stayed bone dry. When it is leaking, there is a trail of wetness coming from the bottom of the AC evaporator coil. It appears to me it is leaking around the evaporator coil, but only rain water is leaking. I ran it through a car wash a couple of time with no leaks. Earlier in the year, it had rained and some rain water leaked inside. I ended up taking it to a mechanic. He was able to put more silicone on the bottom side of the drain where I was not able to reach from the top side. Late last week, we got our first serious rain. When it started raining, I noticed some water on the drivers side. I quickly went down and picked up a car cover and was able to get it on before the majority of the rain hit. After the initial 5" of rain, the car was still relatively dry. Sometime late Saturday night, the wind picked up and the cover blew off the car. Overnight, we got another inch of rain and a sizable amount of water got into the interior. Not sure what to do next. The mechanic was familiar with this issue and has a copy if the service bulletin. This is the fourth Galant he has tried to fix and none have been successful. I am open to suggestions. Just remember, telling me how to keep AC water from getting into the car does not help me.

I give up. I no longer have the time to work on this car. Even though my GTZ is the best car I have ever owned, I cannot continue to deal with water leaking in when ever it rains. I have decided to sell. Thanks for every ones help.

Sorry to hear this. I had a bad leak in the rain as well, and the whole passenger side and rear floor got completely submerged in water. I had tried all the tricks in the book and finally took it to a Mitsubishi dealer, who called someone called the "Leak Doctor", who is a company specialized in finding leaks in cars especially after body damage. He did a pressure test, identified the leaks and fixed them, since then I have had no leaks in the car even though mine is parked outside and is exposed to all the elements for the last 5 years, since I got it done. You might want to try checking with a body shop if you have a similar service(leak pressure testing) in your area.

Pull the wipet cowl off. There are these little black rubber squares beneath it. Seal them up with some caulk and the problem will stop. Doesnt have to be pretty, you'll never see it.

had the same issue with mine and in Florida its a big deal, turned out to be gaps in the weather strip lining around the door, i assume from locking the keys in.....multiple times apparently (previous onwer, i have a spare lol). used plastic bags and electric tape.