Water On Driver Side Floor Of My Car

water on driver side of car

I have a Mitsubishi Eclipse GT, and my radiator has rust in it and my driver side floor is soaked with water?. My fluid in the radiator was low and I had my heater core replaced about a month ago. What could be causing this to happen can the heater core be defective or is it the water pump?

Hi there John,

I would pressure test the cooling system to see where the leak is coming from. It could be a defective heater core, or faulty installation or maybe the water is coming from the A/C evaporator and is condensation water not coolant.

There is a drain hose at the bottom of the evaporator case (also where the heater core is located) and when the condensation from the A/C drips it uses this hose to take the water outside the vehicle and not on the interior floorboard. Maybe the mechanic kinked the A/C drain hose, or forgot to reattach it to the A/C evaporator and that water is dripping inside now?

I have also seen leaves and pine needles fall onto the “cowl” the plastic area where your windshield wipers are located, and fall down into the evaporator case and clog up the drain. You can sometimes take some compressed air and blow out the drain from underneath the vehicle.

Here is a good video showing how to clean the A/C drain

Coolant will feel slightly greasy to the touch, water from the A/C will just feel like water. Run your hand on the carpet then run your hands together, does it feel slick like grease or does it go away after running your hands together a few times…plain water will go away quickly with no residue.

The water pump will not have any effect on water on the floor, so I would not suspect a problem with it.

A heater core leak usually leaks on the passenger side, and a A/C drain (plain water) leak usually happens on the driver side floor or in the middle center section of the floor. When you make a hard or fast turn, the water will splash out of the evaporator case and onto your feet sometimes as you drive…or somewhere inside the vehicle.

A leaking heater core will also make the interior of the vehicle smell sweet, and cause the windows to lightly fog up with a greasy feeling film. The smell and the fog will get worse when you turn the heater fan on high.

Please share this with your friends
Austin Davis

Posted in: A/C and Heating

Got Something to Say?