[Marklee]

Hey Deb,
This is kind of a long shot, but check your cabin air filter and see if it’s wet. If so, some water is getting in and coming down the cabin air inlet vent, which is just under the passenger side wiper mechanism.
It’s a hard to access area but a common entrance point for rodents.

 

[FJC-MAN]

I dug up a couple of illustrations in the repair manual. The lower pic on page AC-38 is showing where the drain hose goes through the firewall. The pic on page AC-42 shows where the drain hose attaches to the heater/evaporator case, like dead center at the bottom towards the console.

 

[debFJVT]

@Kaiju sounds like an excellent ‘last resort’ - will keep that one in my back pocket - thanks!
@Marklee never thought of doing that - duh…and yes I’ve had mice in that area before, leaving goodies and eating filters 🤨
@ FJC-MAN thank you for researching the repair manual on m behalf! I’ll take this outside and hold the drawings up for comparison to get oriented. Is the drain hose in AC38 the same one that carries water from the hood vents down to exit under the vehicle? Are you thinking there may be a leak around that seal in the firewall?

 

[debFJVT]

Here’s how the cowl light wiring is routed - didn’t see any way it provided a route for water invasion - I marked in red (not my red flashlight) where the wires go inside the black conduit and under plastic before heading into the engine bay. Gawd I can’t wait to remove all that messy silicone!!

 

[debFJVT]

Also discovered a drain with plug in the passenger footwell, so next I plan to build a ‘dam’ (rags) on the floor and pour water down the air intake topside and WATCH… see where it’s entering the cabin!! 💪 All the water will drain harmlessly out the drain hole, sitting just above the body mount.

 

[FJC-MAN]

@Kaiju sounds like an excellent ‘last resort’ - will keep that one in my back pocket - thanks!
@Marklee never thought of doing that - duh…and yes I’ve had mice in that area before, leaving goodies and eating filters 🤨
@ FJC-MAN thank you for researching the repair manual on m behalf! I’ll take this outside and hold the drawings up for comparison to get oriented. Is the drain hose in AC38 the same one that carries water from the hood vents down to exit under the vehicle? Are you thinking there may be a leak around that seal in the firewall?

Maybe it came off the heater/evaporator case end where it’s attached (AC-42).

 

[Kaiju]

You'll probably have to pull the right hand antenna cowl and grill. Get some new clips first. I'll peruse my shop manual for you, but since air has to come in through the cowl vents, water is not draining away from the internal openings to the HVAC and is going inside instead.

 

[Kaiju]

I peered into the right hand cowl vent on my FJ. There is an opening in the bottom that air and water travels down through. There must be a body drain somewhere for the water to drain. Where that is, I'm not sure. I'd have to pour water down there and see where it goes. I'm guessing your cowl drain is blocked with debris of some sort, allowing water inside.

Red arrow points to square body opening. My camera wouldn't focus on it.

According to my manual, that entire cover comes off to service the wiper motor and linkage.

 

[AZted]

Hang in there, Deb! I know these pesky issues can drive you crazy. But, if anyone can get to the bottom of this it's you!

 

[ZerosFJ]

Purchase a trombone brush. People like me who own convertible Miatas have to clean a really twisted water drain path for the top, both hardtop and softop, otherwise water gets into the cabin floor behind the seat. Find one with the thinnest rod you can get. Mine is made of spiral stainless steel.



View attachment 1259702

Alternative to this is a cleaning tool for a hydration pack hose (Camelbak etc) may be easier to find.

With regards passenger footwells filling with water I’m not sure /can’t remember on the FJ set up but on my old 70 series there were drains running down the A pillars into the sills and then it drained out underneath. But the drain point was a tiny ‘pleat’ in the metal interface which clogged up with dirt really easily. I used to keep the end of a cable tie in the slot and it was perfect for keeping the drain working and I never had a water filled footwell again.

 

[debFJVT]

Thanks @ZerosFJ I will soon be outside and watching where/how water enters the cabin - I really don’t know where that “pleat” could be….gonna let the water tell me.

 

[ZerosFJ]

On the 70 the drain is front third of the sill. Along the flat edge where the metal meets. From memory the FJ has a couple of drain plugs in the bottom of the sills. Worth pulling one out to see if water is in there (once the sill is full it backflows into the footwells)

 

[debFJVT]

So I did the experiment with watching the footwell/firewall while water was being poured into the air intake up at the cowl - saw water entering around the interior lower A pillar, but not able to see where exactly it leaked in. How could that possibly be a NORMAL route for water?? I’ll be repeating the test today on drivers side to see if it’s the same before jumping to any conclusion.

@ZerosFJ I pulled every drainplug I could find and did not find standing water - but did see rust (some very serious) and some were damp. The underbody on drivers has a hole 😳 and I will go to a well-known body shop soon for a repair.

Wish I’d known about this earlier…warning to everyone, pull all your underbody drain pugs to check for rust and let them dry!!

 

[debFJVT]

Most of the drainplugs are underneath and easy to reach, but in the cabin you can reach under the floor liner (or ‘simply’ remove the seats and entire floor liner) to pull the plugs. On drivers side I ended up just blowing air into the underside as I didn’t feel like hassling with the dead pedal. All dry now and ready for the next experimental water pour…stay tuned!

 

[norm356]

The water path for the cowl drain is meant to be forward of the (dry) cabin area, all of the way down to the ground. But immediately rearward of the Hood Hinge is the dash and A-Pillar area, and those are dry / interior. Any holes drilled into those areas can leak water into the cabin.

Once you get all of the trim out of the way (wheel liner, cowl top panels, etc.) it will hopefully be visible.
I had been wondering if the front fender would have to be removed to be sure of where the entry point is and repair, but re-reading post #24 that ditch light (cowl light) wiring, and its mounting point, jumps to the top of my list of suspects.

 

[debFJVT]

Thanks for the reply, @norm356 No holes were drilled in the A pillar area to install the cowl lights. Removing all those parts would be an enormous task for me, so I’m hoping to find the leak source elsewhere. At present it seems to be on the interior side of the A pillar, and a mystery as to how it gets from exterior to interior. We have had a lucky weather period of dry, but wet times are coming as of Thursday. Next week I go to a body shop for the underbody repair and will ask about the A pillar leak if I haven’t figured it out by then.

 

[debFJVT]

Water pour on drivers side exited as it should, no water leaking into the footwell 👍 I’m stumped on the reason and route of leakage on passenger side…time to go ask other “experts” (hopefully). Tomorrow - Toyota. Next week, body shop. Rain starts on Thursday….

 

[1suffolkmare]

Water pour on drivers side exited as it should, no water leaking into the footwell 👍 I’m stumped on the reason and route of leakage on passenger side…time to go ask other “experts” (hopefully). Tomorrow - Toyota. Next week, body shop. Rain starts on Thursday….

I've used the line from a string trimmer to clean out drain lines. It works well for me. Good luck. I've been chasing a leak in a 2004 Lexus RX330 for a year now. I've learned more about dismantling a car than I thought I'd need to know. Still not fixed.

 

[debFJVT]

I've used the line from a string trimmer to clean out drain lines. It works well for me. Good luck. I've been chasing a leak in a 2004 Lexus RX330 for a year now. I've learned more about dismantling a car than I thought I'd need to know. Still not fixed.

I know what you mean “ learning more about dismantling” and then “still not fixed” !! But I’ve yet to find the actual drain lines to clean out - where they emerge and where they connect to the drain holes on the hood/under the black plastic grates. Good idea to use trimmer line 👍

 

[ZerosFJ]

Water pour on drivers side exited as it should, no water leaking into the footwell 👍 I’m stumped on the reason and route of leakage on passenger side…time to go ask other “experts” (hopefully). Tomorrow - Toyota. Next week, body shop. Rain starts on Thursday….

Just an idea but repeat your experiment with some dye in the water. hopefully it will leave a stain along it’s path which may show when you start to strip things down.