Toyota Corolla - where the heck is this water coming from?

I have a 2003 Corolla that accumulates water on the passenger side floorboard. No big deal, right? Here’s the kicker: The floor mat is not wet, only the carpet underneath. I have tied the occurence of the water to when it rains, but I would accept that could be my imagination.

It happens in winter or summer.

There is a “drain hole” in the floorboard right at the location where the water accumulates - which, by the way, is directly under the passenger’s feet, not any further toward the vents or the front of the car - but the dealer refuses to believe that water is coming in from the drain hole which has a rubber drain plug in it.



It’s possible the water is working its way in via a plugged drain at the fresh air vents situated below the windshield.

Got sun roof?

thanks for the replies.

how would either of these scenarios lead to water UNDERNEATH the floor mat? the floor mat is dry and there is no moisture toward the vents underneath the windshield. also, the wetness is localized to the area immediately around the drain hole and drain hole plug.

I had a similar problem with my 2000 Blazer when I bought it in 2003. The water appeared to be coming up through the carpet on the driver’s side. There was a leak in the seam between the firewall and the inner fender letting water in from the windshield vents. I found the leak by running water into the windshield vent/grill and looking under the dash. I could see the water coming in at the seam and running down the firewall behind the carpet. The Blazer had been in a minor accident before I bought it probably causing the leak. A little silicone caulk in the right spot and the leak was fixed.

Ed B.