Town Car "wet passenger floor" fix

Slick Fan

Senior Member
This should pertain to the 2003-2011 Town Cars.
Okay, so whoever brainstormed this cowl fresh air design needs to be slapped. Then the guy who signed off on the design needs to be slapped. Probably multiple times each!:D

The problem;
After a good rain, your notice your right front & possibly rear carpets are now curiously soggy.
Assuming your windshield seal isn't leaking, the culprit is most likely the fresh air intake plenum for your HVAC system, located just under the right windshield wiper.

The fix;
1) Open your hood, remove the two screws that hold down the outer vent grille, near the base of the windshield. Remove the grille. At this time, you can also peel up the hood-to-cowl weatherstripping that contacts that particular area. There's no glue involved here & it re-installs by simply pushing back on.

2) Remove the 5 screws (8mm hex) and the 2 larger nuts to the right, from the cowl plenum. If the area is filled with leaves & debris, use your wife's favorite vacuum (with the appropriate hose attachment) to suck out all non-car matter.:D

3) Carefully pry the plenum loose from under the grille to the right. Take note how they slip together. Once loose, this rubber sponge-like seal is the culprit that allows water inside your car. Mine is missing a piece on the side...

Also, examine & clean the drain area with the rubber flapper.

4) Clean up any dirt/leaves/etc. from the area...and use that same vacuum if need be!
And by the way, in the very left of this fuzzy (sorry) photo, there is a sponge-like item that is either there to hide "unsightly" fender bolts, or to simply serve to retain moisture in this area for as long as possible. I removed it & didn't put it back...that fender bolt might thank me one day. :D There's it's twin on the other fender that I'll also remove at some point. But, I digress...

5) If your seal is soggy, the moisture may actually help to release the sticky side from the plastic (mine came off in one piece). Once off, dry both the plastic & the metal cowl, then clean both with contact cleaner or brake cleaner...the idea is to have no oils left on either surface.

6) Armed with at least 1/2 tube of silicone sealant, lay a nice thick bead on the plastic surface. I also gooped up my front screw holes (seen in previous photo), but thinking back, this is probably entirely unnecessary.

7) Reinstall in reverse order. On my particular car (I assume all are the same), once I reinstalled the plenum, I noticed the rear half (nearest the windshield) didn't squish down as much as the front half, leaving a gap that water would slip past. So I screwed a nozzle onto the silicone tube & laid down a definite excess of silicone to fill the gap.
So, you may want to lay down a double-thick gob in that area before you reinstall the part. Then double check with a bright flashlight, to make sure it's enough.

8) The car's interior will now REEK of silicone! If you can park it with the windows down, I would strongly suggest that.

Examining the carpet! (with pics)

Slick Fan

Senior Member
Okay, now it's time to examine the soggy carpet. I strongly suggest pulling it up & getting it dry as soon as possible, to avoid mold & mildew. In my situation, the car was parked with the nose pointed downhill during a big rain storm, so the rear portion stayed dry, only the front was wet.
This is what I did;

1a) Remove the kick panel, starting with the back end first.

1b) This is held down with wide metal snaps, so grab the plastic on either side approximately where the snap is & carefully pull upward while rocking it side to side.

1c) The front is held in with one round snap. It's sort of delicate, to take it easy...rock back & forth, while pulling rearward.

2) Pull the carpet back & sop up the water with a towel. Then shove a new towel under there, lay the carpet back down & squish it with your feet...remove the towel, insert a fresh dry one & repeat. Continue until the towel comes out damp, not soggy.
Then lift the carpet up & stick something in there to keep it off the floor, so it can air dry. I used two 2x2 boards.

3) Now look at the firewall pad. Squish that thing & you'll get more water! I rolled a towel on the floor, then pushed the pad with my foot, to squish out some water. Then, I flattened a gallon water jug, and shoved it in between the pad & firewall, to let as much air in there as possible.

The only way to really do this right would be to remove the HVAC unit & pull back the whole pad...I'm not that desperate. :D
It's going to take a few days to dry, so make your passengers sit in the back.

Forum member All2kool has a great idea to help speed the drying process;
To wick the remaining moisture out of the car, buy a cheap colander (Dollar store) and a package of Dry-Z-Air. Set the colander in a dish (Dollar store again) that will hold water but not so shallow as to allow the colander to reach the accumulated water.


New member
I had too do the same to 03 Tc it was a easy fix
What about the tube that runs down the inside of the right cowl. I was told it was plugged. The body shop told me they unplugged it, never had an issue since, and mine always was wet on the right side floor mat after rain...