Originally Posted by Matt24138
I have been chasing a leak forever I have done all the suggestions. First check the drain hose on the firewall and cut off the bottom where it is tapered. Helps to avoid clogs. I am now replacing my windshield frame and doing my 4th cowl seal. If you do the seal make sure you loosen the hinge bolts and push down on the frame. This helps get proper preassure on the seal. Good luck I have spent several hundred dollars and a bucket of money on this issue. I wouldn't care except the water dumps on my fuse block and I lose my headlights and wipers. Not good in the rain lol.
OP, if you haven't done this yet, check it next. It is a short, large diameter black rubber tube hanging from the bottom of the cowl intake and it is right against the middle of the firewall. Up high in the engine compartment. It will look flat or tapered at the bottom and notoriously fills with silt, mud, gunk, and clogs up, resulting in water collecting in your cowl intake and finding it's way into your floorboards/dash. I didn't cut mine at the bottom like Matt suggested, just take it off and clean it out from time to time. It's simple to get off there and clean.