Please understand (for your own benefit) that this is about as
condensed as I can make this, especially since I unfortunately do not
have pics from when I performed the fix It may be a little tedious to read, but take it all in slow and then read again while you go out and tackle the job.
So, if you don't want to read all of this and would prefer "cliff's
notes".....then just continue enjoying the smelly water in your carpet.
If it falls straight to your seats, then it'c oming more from the window-to-targa mating surfaces. The door's windows tend to rub wear marks into the targa's seal and could be part of the cause. When you find water on your seat, are you also finding it dripping down your door's window? Apparently, the mating surfaces of the targa gasket and the door window are "weak". The easiest way to begin weeding this out would be to spend $35ish bucks on a new targa seal for that side and go from there.
The only downside to that is by replacing that targa gasket, you'll most likely (I'm tempted to say definitely) disturb the gasket-mating surfaces even more....requiring further trial-and-error positioning of the new gasket.
Take comfort that none of this is impossible though.....as I'm very proud to say that I beat the shit out of all my targa-associated leaks 100%.
You'll just need some patience and persistance. But it did help me a lot thought that I had worked in bodyshops for 8yrs+, and had some experience with dicking with seals before, and understanding how they pull off and mount onto the car.
A true fix:
I've perfected this fix and performed it on 2 seprerate mkiv's. If all
checks out, and all tips are followed, you will be done sealing water
out of the car and crucial areas of the gutter. The goal is to keep
water from entering under the targa, beyond the gasket and into the interior of the car. A chain is only as strong as it's weakest link.
I discovered the water's entrance points by process of ellimination,
while sitting in my car with a flashlight, interior removed and during
a rain storm. That's how I found the various entrance points of the
water, and learned to approach them seriously.
I did this to my car about 2yrs ago or more. I have not had a single leak
on my carpet ever since. It holds up fine without a car cover and
during any rain storm. After applying the dynamat adhesive backing
where I advise, you'll see how little toyota spent on truly sealing
down the gasket. So, that's what we're fixing.
These corners of the roof/A-pillar are very sensitive to the leak
points discussed down below, but the dynamat adhesive works perfectly
since it's pliable (sp?) and doesn't dry hard or messy like a glue. And
since it's not a permenant adhesive for the gasket, it can be
repositioned as needed throughout the fix!
THE PROCEDURE:
Forget the targa all together for this info. The targa is not at fault, unless you clearly see water dripping on your seat from the window + targa + A-pillar junction.
If you have water collecting on your floor by the kick panel, then read on!
Have a scrap piece of Dynamat on hand. For those that may not know,
this is found at car audio stores for sound deadening. But you only
need a scrap size piece.
You'll need to peel chunks of the rubbery backing and squeeze them
together into thin strings....they'll be layed out along the crucial
points of the roof corners that are lacking sufficient sealant from
Toyota. This is what will keep the water out, instead of using messy
glue that you can't reposition. It is perfect because it's easy to
reshape/reposition as you work to cure the leaks. This is a very nice
advantage over glues!
Remove interior headliner: sun visors, map lights etc. Get it all out
of the way and remove the 2 nuts in each corner that bolt the seal to
the body.
Remove the "eyebrows" in the gutter system.
Remove that 1 long seal that runs the length of the windshield --->
along the entire A-pillar, from 1 side mirror to the other. Gently pull
the seal free from the car by whatever glue it has. Completely expose
the corners where the drainage system is located. It will be a little
tough to remove the gasket from where the studs go through the body
---> gently work in that corner, pulling the gasket free while
pushing against the studs from in the car with a blunt
tool...simultaneously "chipping away" at the sealant holding it down. I
used the back of a large screwdriver to press against the studs while
working the glue loose.
Now collect your Dynamat backing and squeeze and roll it all together
into a single long string, about 8-12in long (you can stick it to your
windshiled where you can easily grab more pieces)......
THE CORNERS OF THE ROOF, IN THE GUTTER SYSTEM IS WHERE YOU'LL BE CONCENTRATING ON SEALING UP:
This is where Toyota got lazy with the sealant/glue.....the gasket
itself is very well designed and not particularly at fault. By the way,
a new gasket is under $100 (If I remember correctly) if you think you
need a new one for this job.
**The Dynamat adhesive must be layed out along the entire perimeter of
the drainage system (NOT the entire gutter system in the roof, but the
small plastic assembly in each corner that the clear drainage hose
connects to).
**Lay the adhesive along the sheetmetal edge that the headliner hangs
onto!!! Again, we're worried about the corners; along where the
drainage is at each corner of the windshield....not along the entire
length of the roof's gutter.
**Lay the adhesive in a circular fashion, ON THE GASKET ITSELF,
immediately around the hole in the gasket contacts the hole in the
plastic drainage piece ---> the hole in the gasket and plastic that
feeds to the clear drainage hose. ***Squeeze this piece of dynamat
adhesive into a more thin strip so that it's not so bulky and clogs the
drainage hose during reassembly (it WILL/CAN happen).
**Squeeze a few more short (1/2 inch), skinny pieces of dynamat
adhesive and lay them around ALL of the holes that the "eyebrows" bolt
to (3 screws for the eyebrows I think). The adhesive will seal the
screws and their holes from water.
**Lay a string of dynamat adhesive onto the gasket, around the base of the studs that bolt the gasket to the car.
Reassembly:
Once all of the dynamat adhesive is in place, you can begin installing
the gasket at the corners. You MUST pay attention to the hole in the
gasket that connects to the drainage hose. This pathway must remain
open so that water doesn't back up in the gutter and leak into the car by way of the other discussed locations. I actually chased my tail over this for a little while....
Once the gasket is pressed down into position, install the 2 nuts are
bolted on snug. If all is good, continue installation by pushing firmly
onto the gasket so that you mash the dynamat adhesive tight and
flat....this helps the gasket sit down fluch where it needs to be.
Again, you need to test the drainage hose to confirm that the path is
clear (it clogs easier than you'll think upon reassembly). Use a cup of
water and simply pour some into the gutter, while watching that it
easily passes down the clear drain hose in the car.
A tip is that you can use a round tool (like a medium sized allen
wrench or equivelant) to stick through the gasket's drain hole while
installing the gasket along with the 2 nuts. This will help keep the
dynamat adhesive from squeezing into the drainage hole in the gasket
and plastic drain hole etc. while you're pressing the gasket into
position.
Once assembled, you can even peel back the exterior portion of the
gasket in order to peek at the hole and see if the adhesive has
squeezed into the hole.
One final spot for adhesive:
**As we all know, when the targa
is bolted on, you can still see some of the gasket......you can peel
back this small portion of the gasket (but just in the corners) and lay
a skinny bead of dynamat adhesive along the top region of that plastic
drainage assembly ---> right under where you can see the gasket when
the targa is bolted on.
**perform ^this^ last bit of Dynamat adhesion with the targa OFF the car.
This last bit of protection will keep any water from even beginning to
enter the gutter at the corners; avoiding more possibilities of a leak to even begin.
Now continue reinstalling everything, while making sure the gasket is
placed back into it's track all the way down to the side mirrors.
You will need a thin, blunt tool to help push the gasket's edges that
fit into these "tracks". Once done, gently tug on the gasket all along,
making sure that it's fully installed.
Points to understand/remember:
The ORIGIN
of the leaks are in these corners of the gutter system of the
roof.....water SPECIFICALLY enters the car's interior by any number of
these detailed locations:
1) The screws that bolt the "eyebrows" in the gutter.
2) Once water is in the gutter and under the gasket, it gets backed up
and drips into the interior along the sheetmetal edge that the gasket
slips onto ---> is also exact sheetmetal edge that the headliner
slips onto when you reinstall it to the gutter (opposite the clear
drainage hose).
3) At the gaskets studs where they enter through the sheetmetal.
4) At the extreme corners of the gasket/A-pillar ---> right past the
little plastic drainage assembly for the clear hose, as the gasket
makes it turn in the direction of the side mirrors.
Yet another detail that should at least be acknowledged:
The last test that should be performed is with the targa bolted on the car. Notice that the front edge of the targa will very slightly pull down on the gasket from the downward torquing of the targa
mounting bolts. This very slight tug on the edge of the gasket's
exterior edge is enough to allow water to seap into the gutter system,
underneath the gasket (actually, it would probably seap in there
regardless).
If you pull the gasket out after a decent rain, you will see that water
gets completely under the gasket. You may even find some minor rust in
the bare gutter like I did....
This is the outermost edge that I briefly mentioned somewhere in the
first post. It's immediately above the plastic drainage assembly in the
gutter.
This is the last region of the gasket that should be sealed down with a
skinny strip of adhesive, while connecting this strip to the lower
portions elsewhere below the gasket.
Optional: This skinny strip can be continued completely from left to
right corners, along the length of the windshield; connecting and
further sealing the left and right corners from water entry at all.
However, I didn't find a need to go this far....and I didn't because I
wanted the gasket to lay natural against the car as the targa is torqued down. But in the corners, it serves a nice purpose.
Final thought or FYI:
The reason water is found on the floor by the kick panel and hatch
release is because the water gets into the sheetmetal above the
headliner, gets redirected to the side/corner of the A-pillar (lowest
point of roof), drips into the plastic interior trim, carried down to
the side of the dash, behind the kick panels and then onto the floor at
the hatch release.
Yes, if the gutter is backed up or draining really slow, during a rain
storm it can fill and then enter through the eyebrow screw holes,
and/or it can leak over the top edge of
the gutter's sheetmetal (from seaping under the gasket) and into the
interior ---> the portion that I described earlier as "opposite the
drain hose".
Water should not be underestimated....it will travel where it wants to travel, regardless if we think it's unlikely or not!
Also: When testing the gutter and drain hose, when the fix is properly
performed you will see that the water will easily flow into the clear
drain hose. And the gutter should empty fast.
If anything is slow moving, then something's not as perfect as it can be!
When i was done, it flowed like a mad river 
Standing water will find the next easiest place to travel.....into the interior eventually.
Originally Posted by Blk96SupraTT
If it falls straight to your seats, then it'c oming more from the window-to-targa mating surfaces. The door's windows tend to rub wear marks into the targa's seal and could be part of the cause. When you find water on your seat, are you also finding it dripping down your door's window? Apparently, the mating surfaces of the targa gasket and the door window are "weak". The easiest way to begin weeding this out would be to spend $35ish bucks on a new targa seal for that side and go from there.
The only downside to that is by replacing that targa gasket, you'll most likely (I'm tempted to say definitely) disturb the gasket-mating surfaces even more....requiring further trial-and-error positioning of the new gasket.
Take comfort that none of this is impossible though.....as I'm very proud to say that I beat the shit out of all my targa-associated leaks 100%.
You'll just need some patience and persistance. But it did help me a lot thought that I had worked in bodyshops for 8yrs+, and had some experience with dicking with seals before, and understanding how they pull off and mount onto the car.
Exactly..... you can have all new rubbers but the leak-free factor almost completely relies on sealant placement.
New gaskets are nice, especially if you're replacing torn ones, but the leaks can get much worse from disturbing the factory placement of these gaskets. So guys will install new gaskets and their leaks will either remain, or even become worse.
Basically, if you need new gaskets, get them....but during installation, follow my thread here for the sealant cure
These gaskets must be tediously placed with much patience and attention to positioning detail! This proper positioning comes from trial-and-error and test fitting. The new gaskets will not fit identically the way the original, old, flattened gaskets do.
It can take multiple repositioning to get them dead-on per vehicle (**especially the ones along each side of the targa roof!)......
that's why the Dynamat adhesive comes in so handy --> you can tug on it and it will come loose since it never dries hard and messy like glue.
Special thanks to:
sean (blkturbo!)
