I may be incorrect but I thought those were used to allow you to release the pressure when you shut the doors.


Sent from my iPad using Tapatalk

 

that is correct, if you go wading in water deep enough to come in there, it will

 

Post some pictures please.

 

All my fj pics are on another SD but thats it bottom left

 

Thanks for the responses folks.

To Sparky: OK, I hadn't thought of that. It'd be like an old Volkswagen where you have to open a window to get the last door closed.

Thanks PatriotFJ for the pic - even got the color right!

Here are some pictures of the damage. First, a view from outside showing the rust at the bottom of the cavity. Note the small rubber item between the two white plastic pegs. This seems to be a one-way valve to drain the cavity. Unfortunately in my case, it got blocked up with mud.

A view of the cavity from inside:

And, lastly, a view of the damage (after some swift work with a flap disk:

 

Toyota calls that a "duct subassembly, quarter ventilator". P/N for the RH part is 62903-60070.

By the severity and localized nature of the corrosion, I'd say that a previous owner drove that FJ along the beach at high speed, forcing salt water through the vent. Other areas on the undercarriage could have been easily rinsed off, but the salt water in the protected area INSIDE the body shell could not be rinsed, and just sat in there and festered. Even if the water 'dried out', the salt remained, and every time it got really humid or rained, the salt residue absorbed moisture and became actively corrosive again. This dry-moist-corrode-dry-moist-corrode cycle could have repeated for years.

 

Thanks for the name and part# FJTest. I think you're probably on the right track with the salt damage. As I'm in southern Ontario it's going to be due to briny winter slush puddles rather than carefree blasts along the beach (unfortunately!). I checked the driver side and it seems to be absolutely fine so, probably a combination of the blocked drain and salt. I also noticed that the passenger side (bad side) ventilator wasn't sealed as well as the driver side. In fact it was fairly loose. This probably didn't help either. When I reassemble everything I'm going to bed the vent in some silicone.

 

So I have a question, as that’s definitely unfortunate. But my question is there an easy way to check this area for FJ owners? Perhaps without removal of the rear bumper?

 

The little $25 USB "endoscope" cameras on a 6' cable. These can be snaked into anywhere with a 3/8" diameter hole, and allow you to inspect all kinds of previously hidden areas.

 

Thank you, and probably a good investment for checking any number of hard to see spots including this one. I also just went into the garage and was looking, if it’s the same spot it looks like you could get a view of it with a mirror or a scope like you mentioned from inside. Just behind the jack access panel on the driver side. But a scope should make either side viewable with just popping an interior trim panel. I wasn’t aware this spot was a possible issue, definitely good to know.

 

In the last picture that rubber flipper looking thing is supposed to let water out but may get clogged with debris.

Sent from my SM-N970U using Tapatalk

 

I read somewhere a while ago that during a deep water crossing, close the windows, switch the cabin air to recyclic, and turn the fan on high.
I believe water will still get through the exhaust vents but might slow it down around the door jam. Dunno. Haven't tried it.

Sent from my SM-N970U using Tapatalk

 

Years ago I acoustically treated my FJ for installation of a sound system. I blocked both of these ports with a Dynamat like material and closed cell foam. No adverse conditions.

 

"No adverse conditions."

interesting! Those vents are to reduce the door closing effort (to release air pressure during door slam), I'd have expected that sealing them up would have made it harder to get the doors fully latched each time.