Ugggh, water leak after rain

Hi all, proud owner of 2012 SR5 that recently started leaking behind the dash on the drivers side.

To set the stage:
Moonroof drains flushed but leak still happening;
After a heavy rain, truck was parked, son went to drive it, heard water sloshing around and whoosh, a ton of water soaked his left foot;
Repair shop drenched with a hose for 30 minutes and couldn’t reproduce the leak. Help!

 

Not anything informed by your post but have you made sure the AC drain tube on the right side, under the vehicle is clear? It’s a common culprit but I recognize it might not be it here but it’s so common it’s worth a peek.

 

Agree with icebear, that would be the first thing I looked at - especially since you said your son heard sloshing. Left foot makes that less likely as a cause though but it is so easy to check that it makes sense to do so. Not sure if this was the case with a 2012 but with my 2020 the drain line is easily accessed under the carpet in the passengers side footwell. Can also get to it from the wheel-well. Another thing to look at is the seal around the bundle of wire that passes through the bulkhead. It is under the dash up and to the left of the brake pedal in mine. Again, the sloshing with the sudden dump of water makes this less likely but also an easy check. The slosh and dump you describe makes me think it is leaking somewhere around the windshield, running down ... something ... and collecting ... somewhere. Less likely might be a door seal.

I feel for you though, I have been chasing a smell / leak in my 2020 for a while and just found it last weekend. Mine was a roof-rack leak though which is way less likely in your case.

Mods: Given the number of threads on here relating to leaks it feels like we should consider a sticky thread where folks can post the particulars of their leaks, methods of investigation and how they were resolved. You inevitably end up having to remove a LOT of plastics during your investigation so info on how to do that properly and in what order would also be helpful.

 

I thought my drains were open too. What I found was that there is an X shaped fitting at the bottom of the drain tube that effectively reduces the drain diameter to about 5 mm. Running trimmer line down the drain pokes through the smutz clog. It appears the drain is working but it reclogs very shortly.

Remove the fittings on both front drain lines. I've had no problems for 3 years now...

 

What's the best way to access the bottom of the drain tube? My 4Runner is in the shop now so I can't tinker with it but I'm interested in doing this.

 

These are all great and much appreciated! I’ll check out these possible culprits and let you know what I find!

For mildewy smell, wife found an idea to run the ac on high, with temp turned to high, blowing at the feet only, 20 minutes with the recirc turned off. Heat dries the carpet and ac dehumidifies the cabin. I’ll give that a whirl as well and see if it helps with the smell.

 

Denver, Remove the plastic kick panel at the floor level in front of the door. The panel you want to remove is close to where your left foot is when you sit in the driver's seat. Same spot on the other side. Good luck...

 

thank you!