Drivers side floorboard leak only when it rains

[mean20004runner]

Hey Gents,

I have a 2000 4 runner SR5 and I get water accumulation every time it rains. The water tends to be dropping from under the dash on the left side of the drivers floor board near all of the electrical harnesses yet they are all dry. I have examined the firewall grommet for sound system lines causing issues and no evidence exists of any water coming from there. I have examined the seal of the windshield near the A post and saw some evidence some leakage could be occurring there and used silicone to fix that but the leak still exists. I have no idea where this leak is coming from. I have looked on many occasions. Does anyone have any similar experiences or fixes they can share?

Thanks,

Hunter

 

[kolelt]

How did you exactly examine the sound wires going through the firewall grommet ? You should spray water directly on those wires. And examine the inside carefully. If it's clean. Then your good there.

Another location, sun roof drains. Total of 4. So examine the 2 front ones. As they drain out where the kick panels are. Yes , by those wires. If you remove the kick panel, you'll see a yellow sponge. Behind it there is a tube. That drains water into your rocker panel. On both sides. Driver and passenger. Then through your pinch welds/little gaps, water drains out. You can blow some air into those drains. To clear them. Check inside your rocker panels by removing the inside side step trim. And make sure it's not flooded. Because maybe your rocker panels are clogged up and it fills up with and gets your floor wet ? I extended my sunroof drains directly to the outside. And haven't had a wet floor ever since.

Another thing, maybe you have a bad door seal ?

 

[simplemind]

Any update? I have the same issue in the same location on my 2014. I thought I had it fixed by cleaning out the sunroof drain, running water over the top, and no leakage. Then today...had a downpour. flooded again! :mad2:

 

[BamaDrewski]

Any update? I have the same issue in the same location on my 2014. I thought I had it fixed by cleaning out the sunroof drain, running water over the top, and no leakage. Then today...had a downpour. flooded again! :mad2:

The source of water can be deceptive and elusive. There is a round plastic plug right under the driver's side floor pan. It will get dry and crack over tiem. Take it out, clean it and then caulk it in place and cover with gorilla tape and lay your factory carpet over it. Chances are, this is where the leak is coming from.

Also, there is an easy way to divert water from coming down the windshield and pouring over the firewall grommet many of us have pulled auxiliary wires through. See here: https://www.toyota-4runner.org/3rd-gen-t4rs/265500-fixed-firewall-grommet-leak-driver%92s-side.html

 

[simplemind]

The source of water can be deceptive and elusive. There is a round plastic plug right under the driver's side floor pan. It will get dry and crack over tiem. Take it out, clean it and then caulk it in place and cover with gorilla tape and lay your factory carpet over it. Chances are, this is where the leak is coming from.

Also, there is an easy way to divert water from coming down the windshield and pouring over the firewall grommet many of us have pulled auxiliary wires through.

I see water dripping from above the floorpan near the fuse box so I doubt it's the round plastic plug, and it leaks when it's just sitting, not driving.

Thanks for the diverter idea. I don't have any aux wires going through, but it looks like a likely source.

 

[Ttiffam]

I see water dripping from above the floorpan near the fuse box so I doubt it's the round plastic plug, and it leaks when it's just sitting, not driving.



Thanks for the diverter idea. I don't have any aux wires going through, but it looks like a likely source.

For me recently it was definitely the firewall grommet. I pulled the carpet back & traced the wetness to there. Touched it up with some silicone on the engine bay side and planning to add a diverter as well.


‘99 Limited 4x4

Sent from my iPhone using Tapatalk

 

[simplemind]

Update: Took the 4R to Toyota service for a water penetration diagnostic exam. Two Master techs tried to find the leak by using a pressure washer and running it through their car wash several times, but could not find one leak. They said it "might be" the windshield, but after having Safelite come out and do an inspection, they checked all the grommets on the firewall, the sunroof drains and finally said it was the factory windshield and that the glue looked to be fully intact and serviceable. This was a free inspection and I did it because I thought they had replaced the windshield, however they had only repaired a chip in my 2010 4R's.
So there I have it, or not have it as the case may be. No resolution to the mystery water leak in a downpour. This is covered as a comprehensive coverage as "flood damage" and at least I could get the carpet replaced, but have no idea how to resolve the problem. :ybrick:

 

[NissanTechJake]

How did you exactly examine the sound wires going through the firewall grommet ? You should spray water directly on those wires. And examine the inside carefully. If it's clean. Then your good there.

Another location, sun roof drains. Total of 4. So examine the 2 front ones. As they drain out where the kick panels are. Yes , by those wires. If you remove the kick panel, you'll see a yellow sponge. Behind it there is a tube. That drains water into your rocker panel. On both sides. Driver and passenger. Then through your pinch welds/little gaps, water drains out. You can blow some air into those drains. To clear them. Check inside your rocker panels by removing the inside side step trim. And make sure it's not flooded. Because maybe your rocker panels are clogged up and it fills up with and gets your floor wet ? I extended my sunroof drains directly to the outside. And haven't had a wet floor ever since.

Another thing, maybe you have a bad door seal ?

Sunroof drain info here is good advice If You have one. This is the most common area I see water intrusion from in customer vehicles.

Only thing I might add is that an old transmission dipstick (flexible stainless cable type) taken from a junkyard makes a great sunroof drain clearing tool.

 

[SilverRidgeRunner1]

:rain:Check out leak tracing powder. Spray the general area and the moisture will be highlighted in the powder left behind takes the guess work out assuming this and that. If the leak is highlighted in the powder as a drip u can typically take a straight edge and pin point it from the impact of the drop and of course if its a leak that produces a trail then the powder will highlight its path...