I recently noticed that the drivers side front and rear floor board of my 2000 Honda accord becomes soaked after a rain.One would think that its coming in through the seals on the doors.I am not convinced.The floor is saturated in one particular spot right in the middle of the floor.With out jacking the car up and crawling under-are there maybe plugs under there that may be worn or missing that could be causing the leak?
Same problem with a 2000 Blazer. I originally thought it was coming up through the floor, but all the floor plugs were intact.
There was a split in the seam between the inner fender and the firewall. I ran water into the cowel vent and looked underneath the dash with a flashlight. Water was running down the seam, going underneath the carpet, and coming up through the driver’s side floor carpet. An application of silicone fixed the leak.
a good flashlight, and a session laying on the floor could enlighten you on the condition of the bottom of the floor boards. the rubber plugs do become knocked out (for whatever reason) and as EdB says, splits do occur. but until you get down and LOOK, how will you know?
i would suspect a leak from the front firewall. like a cable (brake, e brake, clutch, or throttle) entrance.