For the past several years, the passenger side floorboard is always wet after it rains. At first, I thought it was the sunroof, so I used the weed wacker line idea and cleaned out the drains. Still wet. I then went a little crazy with the caulk and sealed up everything that looked like it might leak water when driving in the rain. Still wet. Finally, I gave up and took it to a shop (in fairness to myself the timing belt had also slipped a tooth). They said the leak was the sunroof drains, and they had cleaned them out. Last week it rained like crazy and the floor board was still wet! I finally decided to catch the leak in action and pulled up the carpet, etc, put a towel where I thought the leak would be, and waited for the rain. When it rained I sat in the car and saw this:







Well it certainly wasn't the sunroof! I took off the plastic cowl cover and discovered the culprit! The air intake for the A/C system!



The cracked rubber on the cowl cover was letting water in, and it was getting into the A/C air intake.



It looks like the cowl cover has two trays to divert water away from the intake.



In the case of mine, one looks like it is supposed to "hook" under the windshield glass. Sadly, all the clips to hold the cowl cover to the windshield were broken. I decided to brute force and just seal up the rubber with some black silicone.

In retrospect, I think if I had put the cowl cover back on at an angle it might have realigned the water tray to be under the windshield and catch/divert the water leaking through the rubber seal. Oh well, it poured rain yesterday and no more leak! Hopefully this helps someone else, I'm surprised more folks don't have this issue... of course the first reply to my post might be a link to a whole thread on this topic.

Attached Images

       

nice investigative work! I wouldn't have guessed that

good find, also check to make sure your seam sealer isn't cracked while you have the cowl off, **WATER LEAK** 4Runner Unusual Footwell Water Leak Solution

could this happen due to improper windshield replacement?

I have the same type of problem I think. I have water coming from somewhere in the dash above the a/c drain tube. How do you remove the cowling from the windshield? I had the windshield replaced recently, but the problem started before that. Sometimes the water is gone and then it comes back. I can hear the water moving around too. Stinky smell in my car is building up. 2016 stock 4Runner with 67k miles.

Have someone stand outside with a garden hose while you investigate inside. Do not use high pressure from the hose. Straight out if the hose to recreate heavy rain. Have them move from place to place slowly until you narrow down the water intrusion.

I have a similar issue but I have a wet drivers carpet. Still trying to figure out what it could be. Your post isn’t exactly my situation but the coweling deserves another look on my truck. Water leaks are by far the most frustrating thing to deal with on cars. Especially ones you can’t track down easily!

Not sure if this is helpful but I had to replace the front window side trim piece. That trim piece is held in place by a part that fits into 3 holes that go into the outside of the A-pillar. If any of those are broken that might be letting water in.... Just a thought. the part i'm refering to is 75548a/75549b in the link. You can kind of see the three pins that go into the body in the illustration.

https://parts.toyota.com/images/part...a1_751555H.jpg

i never thought of this but good info just in case it happens to my 4runner, i know where to look. thank you!