After a hard rain I found my passenger side floor damp. I have directed water under pressure at the windows and have found no leak. Can water fill the rocker panel and if so how do you fix it? I sure don't want a moldy stinky car!
There is a TSB with directions on how to diagnose and fix leaks including the cowl channel leaking, possible poorly fitting grommets on firewall, leak around windshield weatherstripping, side windows not sealing properly and AC system condensation leaks.
Seems most likely culprit is the cowl vent area that can get leaf buildup in its drain areas and cause an overflow into front floor area on both drivers and passengers sides but passenger side most probable. Note that with a heavy downpour the cowl vent can leak even if the drains arent clogged if their weld seam was not properly sealed at the factory.
This can be happening for quite some time before noticed because unless the rain is very heavy the floor will be wet under the carpet but still dry to the touch on top. I noticed my problem when I used the heat or when the sun beat down with the windows up after rains and the interior would fog up. hmmmm, why is it doing that?
My 07 had the problem due to poor sealing of the cowl and not due to debris buildup since my car is not left outside except when I drive it. Mine was under warranty so I took it to the dealer and they sealed it with sealant along its weld seam that hadn't been sealed properly from the factory.