Leaking water My 2003 Mitsubishi Galant is leaking water on the passenger's  side and there seems to be water in the heater box too...we can't seem to find the problem, everything (sunroof, firewall) drains  properly but it keeps coming in from somewhere...so frustrating!

sounds like the heater matrix is leaking

Check under dash passenger side, its possible that your a/c drain is clogged (sometimes is necessary remove partially the carpet).

Hope this helps.

most likely from the heater core. it will have to be replaced if it is.--- open the hood and look around the spot the leak is, there should be 2 hoses connected to the body. make sure they aren't leaking. if they, or 1 of them are, just try tightening the clamp or replace the hose.

That sounds like water leaking from your over flow tank? Is it coming from the area behind the glove box on the passenger side? If so, open the hood and take a look at the over flow tank. Is there any fluid in it? Is the hose going to the over flow tank healthy and without holes? Has it come unclipped or unfastened from the over flow tank? Has the tank itself cracked? Is your car over heating? You could have problems with your heater core. Is the water that is leaking hot? If your car is not registering as hot or over heating, and water is being sent to the over flow tank (because it is over heating) which is leaking or the hose has failed ect - then I would also suggest checking your thermostat to figure out why it is not registering the vehicle as hot?

have you tryed to replace your thermostat? if you have a numbered guage on your dash.... has it been higher than 200? if so,then your problem may be thermostat,or a cooling fan not coming on when the engines reached it's standard operarating temperature. as long as you're not loosing coolant from your radiator,does not point to an engine leak.however,if you notice a leak after driving the vehicle,then,you have an issue. determine where the leaks coming from.leaking freeze out plug,leaking water pump,and the worst! leaking coolant into,or,onto the passengers side front floorboard.{heater core replacement} thank you for choosing fixya.com!

Feel and smell the water. If it is slippery and smells like antifreeze the heater core is leaking. If not the drain for the ac evaporator is clogged.

The only time I've ever had water inside on my floor was because my heater core crapped out. Check to see if the leak is coming from your heater box under the dash, if it is it's the heater core most likely.

Is the leaking liquid antifreeze or clear water? Anti freeze is slimy. Ck your AC drain . its under the blower housinfg under the hood on the fire wall. The drain is easier to seeb from below looking yp. Squeeze it open and make sure it's clear. Good luck -Ned_

check all coolant line going to the heater core of vehicle

the probable cause is the drain for the ac coil is stopped up for an a/c leak inside.
if it smells like anti-freeze, the heater coil is leaking and may need to be replaced.