Thread: Water in floorboard (Take 2) - The Permanent Fix

Hey Leon. The GM part is #15794785

Originally Posted by thompo123

I have a 2002 gt coupe with 73000 miles on it.Has anyone developed this water leakage problem on the 2002?I also have a 2006 sedan?
Non of mine are leaking?Did GM modify the cowl after 2000?
Thanks

I had the issue on my 2002 GTP

Originally Posted by peegh

I have a 2003 prix with this problem. I Rtv'ed the strip but saw this write up and decided to replace it. My question to abrasive is. Is there a modification that needs to be done to the new piece to make it work in my car or is the only modification needed done to the cowl only? I will be picking up the new piece tommorrow and would love to get this in as soon as possible. I'm tired of the water in the floorboard and i'm tired of making sure how I park the car so the water doesn't get in. And IMO I would have paid the 15 to have one shipped. I think that it was deserved considering you found the solution to the problem and did the write up. And thanks for the work you did it is appreciated

Only the little flange on the bottom of the cowl has to be removed. The new water deflector goes right in after that, without any modification to the new piece at all.

Some earlier models had a piece of plastic that fit down into the rectangle intake opening, right where the cabin air filter should be if we had gotten one from the factory. It has what look like louvers in it and appears to have been an attempt to help funnel air down into the blower motor fan. If the original rubber water deflector falls off, I can see where it would help funnel water right into the fan. Must not have done much, because GM eliminated it in the later years. My wife's 2000 had it and my 2002 did not. That piece of plastic (if anyone has that) also needs to be removed for revised water deflector to fit. It just pulls right out.

Originally Posted by thompo123

I have a 2002 gt coupe with 73000 miles on it.Has anyone developed this water leakage problem on the 2002?I also have a 2006 sedan?
Non of mine are leaking?Did GM modify the cowl after 2000?
Thanks

Your 2002 has the old rubber seal that tends to fall off and cause the water in the floorboard issue. I would suggest at least pulling the cowl and gluing it in place BEFORE you have a problem (or replace it with the revised part) just to nip water, and blower motor failure from the water, in the bud. Your 2006 may or may not have the new part already. I have found that 2004-2007 Grand Prixs occasionally have the new one already in place. Most don't, but for some reason it's kinda spotty on those years. 2008+ w-bodies should all have the new deflector already.

Can a mod please put the part number in the original post? The GM part is #15794785

I can't edit it because of the amount of pictures. If you could delete the last paragraph also that would be great.

Thanks!

Ok so I did this today and the part was under 4 bucks from the dealer...awesome. Then went to install..sucked. I have the one piece cowl and the pass. side wiper would not come off. Decided to quit being dumb and just try it with the wipers still on. Worked great just be careful not to break the cowl. So if you want to save your blood just keep the wipers on and be careful.

I had the one piece on my GP and replaced it without taking the wipers off. Just set the wipers straight up and be patient.

All you have to do is clean the track in the weather stripping with some sort of solvent like laquer thinner or alcohol and clean the rim on the firewall the same way and RTV the weather stripping back on. Problem solved for $5 for at least 10 years. Genital Motors just forgot to secure the piece of weather stripping to the rim. haha! Whoops 1000000000 times over. Their design is ok but they just FORGOT to glue it down on millions of cars.

*edit* - When I used to do this kind of work for the public, people would come in and say their car had a leak. Soon as I asked them what kind of car it was and went out to see the 3" of water in the floor board, I'd say "I charge $25 to fix the problem." They would always ask why it was so cheap to fix. I'd say "10 minutes and some glue. That would equal out to like $100 an hour. Want me to raise my price?" HAHA some didn't find that funny, but some did.