Water under carpet potential solution

UPDATE: had the leak again, took it back to the dealer. Made it very clear this was the 2nd time I was bringing it in for the same problem and there would not be a 3rd. They had my truck for 4 days and tore apart a lot of it to figure out the issue. It was a hole in the firewall that some wire harness runs through that’s fairly low. Water was splashing up while driving in wet conditions or when pressure washing the truck. They sealed it with a generous amount of silicone. Just wanted to share in case anyone needed it. Lord knows I tried everything I could think of, I just hope this is finally fixed haha.

 

Do you happen to know which hole or where it is located that was the culprit?
I have the same exact problem that's driving me mad right now.

Is the hole in the firewall accessible?

 

do you know where in the firewall the hole was? I’m losing my mind with the same issue.

 

I don’t know the exact location because I finally made the dealership figure it out but they said it was one of the lower holes in the firewall right above the footwell where it begins to angle downward. That’s what they told me. Haven’t had an issue since they plugged it though


EDIT: To add a little context to which hole it might be, they did tell me it was a hole that ran a braid of cable through and there wasn’t a sufficient seal due to the braided cable coming through. Their fix was to silicone seal the shit out of it (super high tech haha), but it worked

 

I greatly appreciate this thread! I have noticed this exact issue beginning maybe a few months ago, and now it's awful. After googling my heart out, I came across this forum and have begun to dismantle parts of my truck to do a process of elimination. If I am unsuccessful on my own, I will schedule an appointment with Toyota.

 

Sorry for the late response, haven’t been on in awhile. I’m super glad this helped ya! Was exactly my intent for creating it. Nothing I found seemed to fix it until I took it to the dealer. It’s been a long time since the dealer plugged the firewall hole and I’m still dry and no smell

 

I’ve been wicked unsuccessful so far. I have checked the roof and removed the weatherstripping and everything is still perfectly sealed. I stopped running it through the car wash just in case, I crawled underneath the truck and don’t see anything suspicious, I took off my passenger side (only happens in backseat on passenger side floor) door thresholds and nothing is wet in the track. I’ve been driving around with large moisture absorbing pouches on the floor in the backseat. I’m finally fed up and bringing it to Toyota.

 

Oh man it’s the back seat floor?? That’s a new one I have not heard of. Is it closer to the door or is it more towards the middle? I’m wondering if one of your door seals may be bad seeing that you have a 2016. It’s not old but it might be old enough for a seal to fail.

EDIT: I misread, I see now you said door threshold area

 

The moisture appears right where a passenger would place their feet on the floor. It was just the backseat passenger side floor, then it started happening to the backseat driver’s side floor too. I removed the long, rubber factory Tacoma mat and have not put it back since I noticed this issue, because it was creating a soft, white fuzzy type mold. The front seat floors are not impacted. God I wish I knew more about dismantling my truck, because that sucker is just begging for me to tear it to pieces.

 

What are the environmental conditions when the moisture appears? Raining I presume, but any other details you can think of?

 

Pic for reference of where I’m at under the truck.


There’s a bunch of these rubber plugs under the truck. This one is right under where the feet would be on the rear passenger side. There’s another smaller one further forward possibly under the front passenger seat. I’m not saying these go through to the carpet but if they are missing, I’d check it out.

 

I keep my truck in the garage when not in use, but it has been raining off and on and the humidity is always crazy here in FL. The moisture grabbers are helping a lot, but it’s still happening. I’ll crawl under my truck again tomorrow. Thank you for your responses!

*Could it be air conditioning related?

 

There are HVAC vents underneath the front seats, so that is possible. I’d say stick your hand under the the seat sometime after driving it around and see if that’s soaked or not. The vent is easy to feel under the seat, it’s got a cowbell shape to it.

Ultimately, if you don’t think you can figure it out on your own, take it to Toyota. I’m ALL FOR trying to figure stuff out on my own but at some point it was either take it to Toyota or lose my f****** mind haha.

 

Thanks for the tip. I am all for trying to figure it out on my own and learning something new, before I ask for help. I aim to be self sufficient and not a “damsel in distress”.

 

No prob, happy to help. I’ve received all kinds of help from this forum, happy to give back. I’d check out the regional forums too. I guarantee there are some helpful people in your area that could help out in person (if you’re comfortable with that). I’ve linked up with a few in my area for some parts sales and helpful info about lifting my truck properly. It’s a great way to meet fellow enthusiasts and get some cheap help haha

 

Greetings,

Where you able to identify where the leak was coming from? The same thing is happening to me and I am getting super irritated because of it. Thanks!