2004 Civic Coupe Water Leak Driving me Crazy!!
 

https://cimg8.ibsrv.net/gimg/www.civ...c4139ded47.jpg
https://cimg9.ibsrv.net/gimg/www.civ...a2ada86ec1.jpg
Hey guys I've got a water leak I've been chasing for weeks and can't find the source of it. It's coming from under the dash on the passenger side. In the corner where the firewall and side panel come together. LX model, no sunroof.

So far I've gooed body seam sealer along that seam where the 2 come together as far as I can get my hand in that crack and it's still leaking right down along the seam sealer. I took the fender off and found a place where I thought it had to be leaking. See pics. The sealer in the pic is where I had put it before taking the fender off. Covered that hole in body seam sealer and hoped that got it. It didn't. MAY HAVE slowed it down but it's STILL leaking. Trying to avoid going thru the hassle of removing the dash and am not sure if I did I'd be able to see the area I can't reach from below due to the ductwork. Gonna pull the fender again and look around. By the way, replaced the cowling with brand new and no stop. Gonna pull that back off too and run some water into that trough and see if anything comes from that area. It's not getting in from the air intake for a/c ventilation.

Thought maybe it was coming from poorly replaced windshield from who knows when but I put some windshield sealant in there and when I taped along both sides of the trim piece that goes down the side if it and sprayed water along it, it still leaked so leak has to be below the windshield right?

Can anybody offer suggestions/ideas on what to check next? Thanks gents!

Re: 2004 Civic Coupe Water Leak Driving me Crazy!!
 

Perhaps windshield seal?

Re: 2004 Civic Coupe Water Leak Driving me Crazy!!
 

Maybe try putting the brightest flash light of any light that you have deep under the dash and then have a look from the outside and see if any light is coming thru?

Re: 2004 Civic Coupe Water Leak Driving me Crazy!!
 

I have been troubleshooting multiple leaks on a 2001 EX sedan.

One definite problem is a broken connection between the sunroof drain tube and the firewall drain valve. The tube seems to have shortened over time and won't fit. I posted a thread looking for fixes to this.

But there are other leaks, I think:

top of windshield: If I run or pour a small stream across the top of the windshield, I get a drop or two from the front edge of the headliner (which is currently loosened around the front and driver side). On my most recent windshield replacement, the local shop told me I had corrosion along the top edge and that they would not be guaranteeing against leaks. They sanded the bonding edge and painted with primer, and said there were no holes...yet. (I suspect one of the driveway windshield replacement techs knifing through the seal many years ago scratched the mounting surface and this started corrosion). I am considering just pouring some of this along the top seal.

below windshield: If I run water below the windshield in the cowling, I get a drips gleaming on the left side inside the firewall. I think this may be one of the firewall pass-thru fittings, for the sunroof tube for example (but unrelated to the separation of tube and valve). Make sure you're not mistaking body filler breaks with one of these hard-to-access thru fittings in the firewall.

I am applying water very carefully at specific locations to try to isolate my leaks. Anything coming down from the roof then down a roof pillar, can look like a firewall leak, but running water below the windshield and getting a leak isolates it to points below the windshield seal (for example). It's tedious and all the while carpet and underliner continue to take up water until all the leaks are fixed.