Persistent water leak OR how Poseidon himself unleashed his wrath on my carpet

Allow me, if you will, to tell you an epic tale. One of triumph and misery, of persistence and frustration. The story centers around a mystical fountain of youth, in that the fountain is a godforsaken water leak and the youth is what I lost trying to track down the stupid thing. :grumpy: Bear with me, word fort coming.

A year ago I noticed that my drivers front carpet and floormat were wet after a heavy rain. I dried the carpet and forgot about it until the next time we had slight rain. Once again, the floormat was soaked through and the carpet beneath it was damp.

I water tested the entire windshield area, thinking that it was getting past the windshield and running down the firewall or dripping off the dash and onto the floormat. After about an hour of being tied into a pretzel, laying upside down under dash with the blood rushing to my head, I noticed water beginning to gather under the LF door. I popped the door panel and it looked like it was coming through the bottom of the vapor barrier. I resealed both front doors and called it a day.

Again, I noticed water leaks on the front carpet and floormats, now on both sides after it rains. It seems to only leak on whatever side is facing up my slightly sloped driveway.

In an extreme fit of rage, I called my Toyota dealer and politely requested a couple new vapor barriers and a roll of fresh butyl sealer. I removed all of the old butyl tape and applied fresh tape. I applied butyl tape to the back of the speaker to seal it to the door. I cut pieces of the old vapor barrier and double gasketed all of the holes for the lower door panel clips, from the inside of the door. I carefully arranged the wiring harness through the door so that any water that drips down would run back inside the center of the door and away from the interior. I double gasketed this area too, and even sealed it again with gorilla tape over butyl sealer. There was no way in hell this was going to leak in anything less than a tide from Moses himself!





Blasted! The next time it rained... the RF carpet was wet. Again. I flipped the truck around and let it sit for a month. I went out today, jumped in and promptly slid on a sheet of ice. Should've worn some ice skates. Note to self, pick up ice skates for the commute to work on Monday.





So, wonderful Tacoma World, I come to you hat in hand to ask... WHAT IN THE HELL IS GOING ON HERE? It's too damn cold to water test, but I would still guess that it's the <expletive> vapor barriers. Could my door seals be leaking even though they look ok and there's no wind noise? Is Toyota trying to punk me into buying a new truck? Is this possibly a known issue that everyone has run into and there's a Sticky at the top of this forum that I could have found with a simple 30 second search? Please oh please help me figure this out before I take my shotgun and make a few extra drain holes in the floor pan.

 

I don't think it's the door seals. If your doors are filling up with that much water, I think you would be having electrical issues too.

 

to get to the floors I would either think heater core or windshield, and I'd lean toward windshield being that its on the drivers side. But I'm not 1st gen expert.

 

Well if you saw it dripping from underneath the moisture barrier on the door panel, then it eliminates at windshield seal leak. Although I am weary of it pooling up that much on your floor pan from dripping under your door panel.

Have you checked the window trim/weatherstripping? The one that seals along the bottom of the window when it's rolled up?

If it was me, I'd take both door panels off, both A-pillars off and sit inside the truck with the doors closed and have a buddy hose it down.

 

Good idea-hose it down-Find exactly where the water is coming from.
Is there a sun roof???????

 

Another thought--DOOR DRAINS--are they clogged?
Door will fill w/water and come out where the panel secures.

 

The thing is... that panel looks pristine. No evidence of water coming in anywhere. Not on the face or in between the two door skins.

 

are you positive it is coming from the door?
Again--is there a sun roof?
Seeping in and running down along the door. Do you see what I am implying. Down hill side has the water.

 

keep your fresh air vent open or closed when raining ?

thought I read that some other folk had issue
something to do with the cowl intake, I thought

 

My wifes old runner had this issue.
Her issue was a clogged gutter under the cowl. The water would run down the windshield, under the cowl, <clogged gutter>, puddled onto driver floor. Took it to stealership, they blew it out & the problem was solved.

Before that, I thought it was a windshield seal. She had her windshield replaced and the wet floor happened within that year.

 

We WANT to know!!!!!!
did you find the cause????

 

Door boots???

 

A technique we use in the sailboat world for leak detection. Closeup truck, pressurize the interior with a reversed vacum hose or aircompressor, spray the exterior of the cab with water/dish soap mixture. Look for bubbles forming.

 

Thanks for the advice. The door drains are clear and working properly, and I wouldn't think that putting the AC in recirculate would make a difference because that just moves a foam-edged door about the blower motor. It's not a good enough seal to stop water. Also, if that were the case I'd expect lower end, not the higher end.

That said, the wiper cowl is a possibility. I noticed that the carpet is also wet at the top edge under the pedals, but there's no water tracking. I'm going to clean out the cowl and water test on Wednesday evening.

 

Had something similar in a dodge neon (I know, entirely different vehicle, but the source of the leak was so surprising I figured I'd share).

In that case, had a similar leak, water in the passenger side after a rain. In fact upon driving right after a rain, water would pour onto the floorboards. After a few weeks of WTF investigation, I was looking under the hood at the firewall and I see what looks like a torn hose (about 3" long, thin rubber, non-clean cut end) that's coming out of the firewall. It was also folded up and kinked.

After doing some research to figure out what's missing, I learned that it's actually a drain for the venting/air system. Somehow, something had caused it to kink, and instead of water draining from the drain, it drained into the cabin.

When I unfolded it, about a liter of water poured out. Problem solved (though not the musty odor).

Point is, not sure if our tacomas have something similar, but might be worth a look.

 

Similar situation with my Taco. I bought it certified, used. Carfax was clean as a whistle, so no big deal. Anyway, after every rain, the driver's side floor from the area above the left foot rest down to the floor mat would always be wet. The windshield had been replaced, so I thought it was leaking. I did every possible test on the windshield and could never find the leak. A few months later, I was trying to find a good place to run the coax for my CB through the firewall. I had poked a hole in a rubber plug below the steering wheel, put my drop light in the engine compartment by the brake booster, then went inside the cab to look for the light. I had pulled the carpet down to look for the light. Low and behold, I noticed two holes. Light was coming through the hole in the rubber plug, and another spot just a little smaller than the diameter of a pencil just above the left footrest. I looked back in the engine compartment and noticed that someone had spot welded the inner fender back to the firewall and burned holes right where they met. I took a hose and let water run down the backside of the inner fender and sure enough some ran into the hole that was burned through the firewall, the rest ran off like it was supposed to. Other things I noticed: stuff not bolted back to the inner fender, the ABS sensors were not bolted up, but were hanging down by their wires, bouncing on the frame. Overspray in the door jams where the tape had ended while the cab was repainted.

So I found my leak. They put some kind of sealer on this joint from the factory, but it had been removed when the spot welds were made. I took black RTV silicone and resealed the joint.

The other thing...I determined my truck had been wrecked. Had water not leaked into the cab, I would have never took the time and seen all the things that hadn't been put back. I'm just glad I never hit anything hard enough to smack the airbag sensors on the frame and cause them to deploy.

 

I spent an hour water testing last night and found three separate leaks. I have a bunch of pictures detailing them in case others have a similar problem. I'll post them this evening after water testing again to verify it's fully resolved. All of the leaks occurred around the door rather than the windshield. There also is a TSB that I'll outline.

 

Waiting for the pictures!!

 

I'm having the same problem - can't wait to see what you found.

 

The TSB covers two locations for water leaks: the cowl and the doors. I only had water leaks in the later, and the TSB didn't really apply except in regards to the way I installed the vapor barrier. This was in fact just a minor cause of water ingress. The major cause I located and repaired myself. If you have leaks from your cowl area, check out this TSB. Note that this particular copy is outdated and doesn't have the additional information about the vapor barriers on the doors.

If you look at your vapor barriers, you'll note that there is a horizontal hole in your door skin, and the vapor barrier is tucked through this hole and taped over with something vaguely resembling the offspring of packing and masking tape. This serves as a drain to prevent water from pooling up between the door skin and the vapor barrier. Any water buildup will flow towards these holes and will run back towards the outside. On one of the vapor barriers I applied butyl sealer all around this section, preventing the drain from working as designed. While I didn't have a leak at this moment in time, the TSB specifically mentions this feature so I repaired it so I wouldn't have problems in the future. By repair, I mean I cut the sealer above the drain and applied tape over the sealer to prevent it from sticking and allow the water to drain out. The following picture shows a properly functioning drain:




Leak number 2 is easily overlooked. Sitting way up high and recessed back, you wouldn't expect this hole to be the source of a leak. Surely enough, with a light downward rain, water would find it's way through this hole and into the cab. This hole is designated by the upper-most arrow:




On the passenger side, I noted that there was a clear plastic plug covering this hole. (see below, yellow dot over plug) Even though it was present, it wasn't sealed at the bottom. I removed this plug, applied a ribbon of butyl sealer around these holes and covered with Gorilla tape.




Now here's the biggy. I didn't honestly believe either of these issues was the major source of water ingress, and I had to have overlooked something. Sure enough, after a while I noticed a trickle of water around the DOOR SEAL at the base of the A-pillar. This trickle turned into a steady stream with the slightest touch to the seal. Bingo. It's hard to see, but if you look in the center of this picture, water was streaming in at the front corner of the seal:



I removed the lower end of the door seal and noted that it pulled off the pinch weld very easily. It came off the front and lower edge of the door easily but it was still quite tight on the top. I also noted a light residue of butyl tape on the pinch weld, which I'll get to in a sec.

Since the door seal wasn't worn or damaged, I decided to repair rather than replace it. My issue after all was a loose fit on the pinch weld, not a hole in the seal. There is a thin piece of metal in the seal which runs around the perimeter of the door and squeezes tight on the metal. Or at least it should. With a pair of pliers I gently squeezed this metal shut every half inch. I applied a thin ribbon of butyl tape over the edge of the pinch weld and reinstalled the door seal, noting that it now fit much much more securely.

Here is a picture of my adjustment to the door seal. To the left of my thumb is the seal as it looked when pulled off the door frame, and to the right is the "adjusted" seal. I was not spreading apart the seal for this picture; the gap really was that loose.




All that's left at this point was to dry the carpet. I have a handy-dandy high volume fan that's essentially a blower motor in a tube. You might not. In that case I suggest pulling up your carpet, and propping it up with rolled tubes of cardboard. Your carpet has a rubber liner between the upper material and the insulation, so this is the quickest way to dry the bottom before mold kicks in. Then: 1.) Turn your temp dial to heat, 2.) Blower high, 3.) Direct air to floor, 4.) Vent to fresh air rather than recirculate, and 5.) Turn your AC on! The later is key. Ask me how I know...




The truck has been sitting outside for the past week, and it rained all day today and once earlier in the week. I went out and checked my carpet a few minutes ago annnnnnndddd.... dry. Finally. Not a single drop of water.