Expert: Roland Finston - 7/27/2011

Question
My parents have a 2001 Chevy Lumina and when ever they use the Air Conditioner, the floor on the inside of the car get drenched in some sort of liquid. They have taken it to multiple car shops and all of them said that the AC hose is plugged and it has been a continuous problem since they bought the car. I was wondering what your advice is. Could there be multiple hoses that are plugged? or could there be an under lying problem that is being disguised? It has now gotten to a point that not only is it wet on the passenger side but also the driver side. Another question, would it have anything to do with there radiator, because from what I've noticed it doesn't smell like engine coolant?

Answer
Rachel,
If it only gets the floor wet when the air conditioning is used and as well the fluid doesn't have any odor of antifreeze, then I suspect that what is happening is that when the ac operates it has the normal function of causing moisture in the air which it cools to condense on the cold surfaces of the cooling fins in the housing under the dash. That moisture becomes frank water when you turn off the system and drips off those surfaces into a drip pan at the lower front edge of the housing. There is a drain hose connected to the pan that is supposed to allow that water to drain out of the pan and pass through a hole in the firewall (floor board or panel that separates the engine compartment from the cabin). Likely that lumen of the drain hose has become clogged so that the water doesn't drain out but rather overflows the drip pan and lands on the rug below it. So I would jack up the right front wheel or put the vehicle on ramps or a lift so that you can get under it and find the end of the drain hose. Then take a stiff wire and run it up into the lumen of the hose so as to loosen the debris that is blocking it from draining the water and that will then allow the pan to resume the draining process for which it was designed. You will often notice that when cars leave a parking spont there is water on the ground, just above where the cabin/firewall joint is located, about mid-body side to side. You want the Lumina to do the same thing. There is nothing wrong with the ac or heater as such, if I am correct. It is an easy fix once you find the outlet on the under side of the car. But someone will need to get under to look for the hose outlet and put the wire up into it to clear the blockage.
Roland