1991 3.1 lumina

When it rains, water leaks from under my dash to the floorboard on the passenger side. It doesn't happen when the A/C is running, only when it's raining. I removed two large pieces that cover the windshield wiper mechanism. These are the same pieces that form a seal at the base of the windshield.

Once I had the mechanism uncovered, I noticed a hole in the frame ~3" X 5" that contains a circular air vent/filter. I put some water in the vent and the water passed through the seal and into my car. When I run the A/C, the vent/filter rotates so I'm assuming the vent is part of the air system.

My questions are: Do I need to replace the seal on the bottom of the filter? Or do I need to replace the piece that forms a seal with my windshield? I'm convinced that rain water shouldn't be in that vent and I need to prevent it from making it into the vent.

Please help! It's really annoying when I get in my car to go to work and there is a pool of water in the passenger floor board.

Jason

I'm still fighting this problem. If the seal on the windshield is bad, would it allow water to pass into the car?

Jaymar

Yeah this is a common problem with alot of GM cars. That plastic at the bottom of the windsheild that covers the wiper mechanism doesnt have a seal. BUT, the open space that is under it does. Heres a quote from a corsica forum I frequent:
Corsicas DO have a habitual leak in the cowl panel where the wiper linkage is. The sealer will dry out and crack, and when it rains,or ya wash your car, it can and will get under the carpet without ya ever knowin' it. If ya take the plastic panels off to reveal the wiper linkage, look at it's "floor" toward the front side very carefully. See any cracks that look like a desert while looking from one side to the other?

Thanks for the reply!! I have a couple more questions to clarify

I've spent about 12 hours trying to find this leak. I tape things here and there and then put water on the windshield to see if the car still leaks. Nothing seems to work. I'm not a mechanic and the description in the quote is not very clear to me. What is a cowl panel? What is it referring to when it says the wiper linkage?

Here is my interpretation: Under the wiper mechanism, there is a "floor." What I think is the "floor" has drains on the left and right side. On the passenger side of the "floor" there is a vent for the rotary fan for the A/C/heat system. Somewhere on the floor, towards the inside of the car (and not towards the motor), there is seal that is cracked and is leaking. How does this sound?

If this is a commom problem I suspect most mechanics will be able to fix it fast. I'm just worried that if they have to spend as much time as I did trying to find the leak, the labor charges will be high. Any advice/info will be appreciated.

Thanks,

Jason

Ill get some pics and post em.