Wetness under carpet

When I bought my truck, which is a 2021 Tacoma TRD-Off Road, it was in the winter. When spring came around with the warmer temps, the truck started having a strong musty smell. At first I was thinking it was from wet floor mats and the carpet did not get fully dry, but It kept getting worse. So, I took it to a auto recon place and the guy pulled up the driver side carpet and it was completely wet underneath and the carpet pad came out in pieces. The guy at the recon place thought whoever cleaned it at the dealer where I bought it from used too much water on the carpet when cleaning it and never let it dry. Well, now six months later the smell is strong again, so I pulled the carpet up and there is standing water under it again. It is only on the driver side and only at the bottom of the of the foot area, there is no wetness from under the dash or near the door. The wetness does seem to go towards the center console, but it is hard to tell.

So now I know it is an issue with the truck, but I have no clue what it is. All the body plugs are in place. I am going to have to take it to the dealer.

 

Did you buy it Used or New, maybe had been in a prior accident? Otherwise, the common leaks can be from a Roof Rack or through the Third Brake Light, possibly even a Sunroof drain tube.

 

Dealer demo. There is no damage or signs of repair underneath. I have check the drain tubes on the sunroof, but there would also be signs of wetness coming from the front left and from under the dash. Also, if the sunroof drain would leak inside that easy, there would be many others with the same issue.

 

Check the windshield to see if it's been replaced.

 

Have you checked the ac drain tube that is supposed to drain through the fire wall on the passenger side?

 

Damn, is this truck not under warranty?

 

The windshield was replaced and it has been checked, but no leaks. Also, it would be wet from under dash down to the floor and the only wetness is where your feet are. So, I ran the truck for about 15 min with the ac on and the drain tube did not have any water coming out of it. Where would if flow if it was blocked? Also, have the driver side carpet all pulled up and I sprayed a lot of water under the truck the area of the driver side floor, but no wetness. It is under warranty so I will take it in to the dealer, I was just hoping to find something myself.

 

I'd guess something is dripping from inside the dash onto the floor.

The musty smell could be any number of things, including the water you're mentioning. Toyotas are known for ACs smelling badly, especially in the first couple of uses after not being used for a while. I notice mine in the spring but it goes away with more consistent use.

Maybe stick some paper down there and when you're driving, periodically look over to see if there are any wet spots. If there are, you should at least get an idea of the area it is coming from. How does the cabin air filter look?

 

Plugged sunroof drains are a fairly common occurrence across all make and models.

 

Had a friend with a Highlander with a sunroof. They had woken up one day with standing water only on the passenger side floor. It was a clogged sunroof draining system. This was in Oregon where there are endless leaves and pine needles. Moss would grow in your taillights if you left your rear end facing north..

 

I’d definitely take it in, I’m not saying it will get to it, but the mold cleanup is very expensive,,,, should it come to that, having it documented would help a lot.

 

dealer demos are some of the most abused vehicles, alcoholic salespeople, crackhead retailers, everyone got a chance to rag on them

 

Had the same problem on my passenger side with my 21 TRD OR. Turned out there was a hole in the firewall that wasn’t fully sealed up with a wiring harness going through it. Any time it rained or i went through puddles, water would somehow splash up through the hole and get the carpet wet under the floor mat. The dealership silicone sealed all over it and never had the problem again. Been almost a year now. Not saying That’s definitely Your problem but it’s one of the less common problems that people don’t talk about as much. I did all the other diagnosing mentioned about a/c condensers and windshields and floor plugs etc, but nothing was fixing it. Unsealed hole in the firewall was my problem

 

I do feel it is coming up through the floor because nothing else is wet around it and the top of the floor mat does not get wet. There is too much in the way under the truck in the frame area to see up in that area. I think I will cut the driver side carpet out from under the seat so that I can replace it without it showing, it needs a good cleaning anyway to get the musty smell out, then drive it with nothing on the floor so that I can actually see when the water starts to come back. I will be able to tell if it when it is raining or not. At least then I can give the dealer a thought as to what it is otherwise they will have it for a week trying to find the issue.

 

I wouldn't try to fix it,, or you risk the dealer blaming your repairs or diagnosing on the problem.
You are not helping them help you,,,, you are painting yourself in a corner.

 

I found the issue. It rained all day so I park the truck outside. It was completely dry on the floor before that and I had the carpet pulled back. Later in the day there was standing water to the left of the dead peddle block and leading back towards the door. It was not wet where I noticed the first time under the feet area, but that area is lower, so it must have pooled there after a while. So, I dried it again then took the garden hose to the front of the sun roof area and within 1/2 minute water was running down from under the corner of the dash area. However, the drain is still flowing on the outside so it does not seem to be blocked. The truck is garage kept and I keep it clean, plus there has been a water issue since it was almost new so I think there is connection issue or a bad drain tube. The dealer will need to take the ceiling off and check it out.

 

This might be your problem and fix. Read post number 127 (last post ) for the fix
https://www.tacomaworld.com/threads/leaking-sunroof-moonroof.658831/page-7

if you get blown off by the dealer , at least you know it’s an easy and cheap fix

 

darn, so this is about a truck? Disappointing...

 

Glad you figured it out!

 

I took it to the dealer and it turns out that the line was just plugged, they cleaned both lines out, let me drive a new 4-Runner for the day and only charged me $50. I have had the truck since 25,000 miles and it is always garage kept and it is kept clean. It was dealer owned before and it must have always sat outside under trees. It is a poor design that the tubes can get plugged so easy and when they do it will leak into the interior. As a warning to all with a sun roof, keep the lines clean. Testing with a hose is not reliable because mine was still draining behind the front wheel like it should be because it was not fully blocked, but it was also backing up into the truck.