Leak in REAR passenger side of 2005 Lincoln Towncar

My father has a 2005 lincon TC that is accumulating water in the rear passenger floor board. Gasket is in place and looks good (I have not checked myself yet though). There is no sunroof on this car.

Any suggestions where to start?

Which gasket are you looking at? The door gasket? Is the door closing correctly?

Check the drain holes in the bottom of the doors, and the HVAC drain tube on the fire wall.

Other possibilities are a leaking rear window seal or truck gasket.

Is there water in the trunk (spare tire well), or just in the interior?

The pass rear and front door gasket was checked. I would not think the firewall drain tube could cause the leak to appear in the read seat area, but I will check. He seems to indicate that there is SOME water in the trunk. Suggested he check the trunk gasket.


A clogged HVAC drain tube will allow water to drip onto the front floor, but the water sometimes migrates to the rear. It all depends on the shape of the floor pan.

Once you find and stop the leak the padding under the carpet will have to be removed to dry. It will not dry if it stays under the carpet, and there isn’t a shop vac on the planet that can remove the water from the padding.

But first you have to find the leak.

There are a couple of places that the HVAC system can leak and water will accumulate in the rear foot well.

One is where the HVAC drains condensate water. There is no tube. You can find the drain by removing the inner fender liner. A seal there deteriorates. It is more like a flashing than a gasket. I saw some pictures of it and a fix at www.crownvic.net.

The other place is the seal between the air intake screen (under the slotted cowel that runs the length of the windshield under the windshield) and the HVAC plenum. Water runs in there and into the front footwell, but it collects in the rear, I think there was a TSB issued for that.