Z3 Leaky Roof
Fastwoman contributed a wonderful posting in this forum on figuring out the cause for her Z3's leaky roof, and providing some great pictures and text of how she fixed the problem. My Z3 also leaks (it has the hardtop on). I thought I might post my experiences so far with trying to fix the leak. Actually two leaks, one on either side near the top of A-pillars.
I took off the hardtop and all gaskets seemed clean, pliable, and in good shape. I poured water into the windshield's gasket's crevice and sure enough, just like Fastwoman said, the water flowed down the crevice, disappeared, and then appeared as a small puddle under the car. Fastwoman said there is a water channel in the A-pillar which is supposed to do this, and it seemed to work fine.
I did find the triangular "plug" Fastwoman talked about, but it didn't seem loose. I pushed it and pulled it a little, but didn't see it separate from its housing. For Fastwoman the "plug" was loose and she added some silicone or glue to reseal it. But in my case I didn't see any water coming out the "plug."
Not knowing what else to do I put the hardtop back on and did a hose test on the car. My driveway is at an angle. I first parked the car with the front higher than the the rear, gave the window area a real good shower from the hose, but didn't see anything dripping.
I next reversed the car, so now the hood was pointing down hill. Sprayed again and now saw water dripping inside. Still, I had to spray a lot water before seeing the dripping.
Next I parked the car across the driveway (perpendicular to the drive way) so it was level (front-to-back) but angled down driver's side-to-passenger side. Then I repeated the hose test and this time water right away started dripping inside.
I put the car back in the garage (which is level). The next morning I dumped 2 cups of water from a Pyrex measure on the windshield area near the A-pillar. No leak. I poured another 2 cups of water. No leak. I filled a 3 quart sauce pan of water and dumped the whole thing. Leak! Dripping inside the car! So right away I opened the car door and it seemed to be leaking from the junction where the windshield's gasket butts up against the hardtop's gasket. This is right where the "plug" is that Fastwoman refers to. I pushed my finger in a bit to push apart these two gaskets but didn't see anything conclusive. Of course by this point the water was no longer dripping.
I suppose the water could have been coming out the "plug" Fastwoman wrote about. I'm not sure what to do next. Maybe tomorrow I'll take the hardtop off again and try to pour and pour water down the windshield and hope to see it come out the "plug."
By the way, it leaks the same way on the other side. I recently bought the Z3 and it came with the hardtop on it. I'm not supposed to raise the soft top until the weather warms, so I don't know yet if it will leak when I put up the soft top.
Opinions sought and appreciated.