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Rain water on passenger floor


This question is related to last show’s question from Steve (but without the ethical undertone; I don’t want to sell or trade in my car). I drive a 2009 Honda Fit (and I am very happy with it). Last week, after some intense rain last week in Greenville, NC, out of the corner of my eye I noticed that there was a puddle of water on the floor of the passenger’s side. I looked for a cracked window or maybe a leak from the windshield, but I couldn’t see anything; besides, the floor was the only part that was wet (the dashboard, the seat, and the inside of the door were completely dry). Today I took the car in for an oil change to the local Honda dealer and I mentioned the issue to them, and asked whether they could take a look at it. They did and they said they could not find a leak anywhere.

Any ideas about where the water might come from? Is this common? Any suggestions on how to fix it or prevent it from happening again?

Thank you,

Got a sunroof? Check the drain tubes. If they get plugged, they can leak into the cabin.

Thank you for the response, shadowfax!
No, I do not have a sunroof and today I had the shop check for any leaks, and they didn’t find anything.

I had a leak in the seam between the inner fender and the firewall in my 2000 Blazer. I found the leaking be running water into the windshield cowl and shining a a light under the dash. The light reflects off any water leaking into the car.

In the Blazer’s case the water was running down the seam underneath the carpet and padding and showing as wet carpet in the rear passenger compartment.

Ed B.

You might need to head to a self-service car wash with a flashlight, a stack of quarters, and a friend to spray the car from outside while you climb around inside looking for a leak.

I have a 2004 Monte Carlo. I have a leak at the windshield front post to door seal. The rubber does not fill the gap between the two pieces of steel that make up the windshield post. There is a very slight groove in that post. So the seal allows a small amount of water to enter there. It travels down the rubber channel that surrounds the inside of the car jamb, not the actual door. At the bottom it sneaks inside the car when it squeezes past the seal where the 2 ends meet at the bottom of the door jamb. This only happens in a heavy downpour. It can usually escape to the door jamb area without issue but a lot of rain it will overflow into the interior portion of the car. I do not have a fix for mine yet but it only happens if the car is nose down on the driveway. Flat or nose up there is no problem, the water escapes fine.

Thank you all for the responses. These seem to be more plausible than some sort of interior leakage from the AC (which was suggested in other forums). I will have an interesting test tomorrow, when Beryl comes over NC.

Interestingly, when I first noticed it, the car had been parked during a heavy downpour with the car nose up on a driveway.

May be a difference in the way water sheds off the car between your Honda and my GM. Also any hole in the front firewall for wiring harnesses or AC and Heat controls that may have caulking missing from assembly would cause water running down the windshield to run down the firewall and into the car. I would expect that to be more noticeable with nose up…

I had a 77 Camaro that water would run down the windshield , across the cowl sheet metal, down the firewall and through the side of the hole for the fuse box. The factory missed applying the 3M sealer to that side of the fuse box hole. That would always be wet though any time it rained on that car…