Water in floorboard (Take 2) - The Permanent Fix

**brandonl2000** · 12-09-2010

I noticed water in my floorboad so I went to the dealer and they had to order the part from Jackson, MS. I paid my $9, got the part today, and attempted it today. whoo hoo.

I want to share that the two plastic cowl retainers BROKE. lol. I had to pry them out with two flathead screwdrivers and they just snapped and broke off in there. So maybe you should add that happens.

I head down to the auto zone and after going back two times I finally got a size to work. A 1/2" nylon retainer. After much hammering I got one of them in beautifully. The other one cracked but we ended up making that one work too lol.

So anyways, I don't know if you can get the proper retainers that go in there but I just wanted to share my experience. I hope the leak is fixed; it seems fool proof anyway.

Great write up

**Reaperblade** · 12-30-2010

I almost made the mistake of taking my 02 GP to mechanic to fix this problem for $50 or more. Happened to run across this write-up, $3.39 and a day later, replaced the cowl in 15 minutes.

Great write-up. Couldn't be any easier.

**dmogie** · 03-05-2011

Are you still selling these?

**DrWho** · 03-06-2011

from 1st post:
GM part is #15794785 It can be bought at any local gm dealer
so just go to your GM dealer

it will be listed as a part for 2004 and higher grand prix's
but it will work on 97-03 with modifications explained in the first post.

I fixed mine and have never had a problem since
cost me 5 bucks for the part
again great write up !

**98GPGT2D** · 03-10-2011

Mint. I was going to try the other fix. It has been raining here in SW Ontario for the last 2 days....The gf and I have not driven the Grandprix in a week, we have been using my Jimmy for transportation because the fuel pump in the grandprix is on its way out. I have already had to pull the pannel in the trunk and give the top of the pump a smack to get it to go, twice since mid Feb.. Anywho, back to the story, ran out to the car this evening only to find an inch and a half of water on the passenger floor. So...tomorrow, the car is going to work with me, im ordering that part, installing it, then shopvac'n the water out of the carpet.

Jay

**quinnp12** · 03-12-2011

Finally put this thing on. Fits the my 02 Grand Prix just fine, fit my wife's 98 intrigue well but it was a little tighter. overall, easy and worth it!

**lcamaya** · 03-29-2011

I'm going to get one for my '99 GT from my local dealer, but I also want to get the right cabin filter. I ordered one for a '99 Regal and it doesn't seem to be the right one. The spot for my cabin filter looks just like one pictured in the original post, but the filter I received is rectangular and doesn't quite fit. Has anyone else had this problem? And does anyone know what the part number for the cabin filter is??

**postalc38** · 03-30-2011

I can tell you the FRAM FreshBreeze Cabin Air Filter is CF8392A. Just put one in today with the raindeflector ($3.59 @ McDonald GMC Cadillac in Saginaw, MI).

You have to make sure the filter actually sits in the housing the right way, the right-hand back corner can be a pain to match up right.

**lcamaya** · 03-30-2011

I'll give it another another shot tomorrow and see if I have better luck.

**lcamaya** · 04-02-2011

Took another look at it and was able to get it that time. It tapers off to a different shape that threw me off initially. Good lookin' out

**SomeDudeAtHome** · 04-27-2011

With all the rain we've been getting this spring I noticed my floorboard was getting wet so i called my local dealer and they had the part in. $6 and some change later my floorboard does not leak anymore. Took my dad and I only about 10 minutes to do. Awesome write up.

**bigern79** · 05-09-2011

Awesome post! Gonna try the dealer tomorrow. In my case the water was bad enough it ruined my airbag sensor which is located under the passenger seat. Took a bit of research to find out why the airbag light was on but when I pulled up the carpet the module had obvious water damage. FYI for anyone who might have the airbag light on and water in the floorboard.

**slvr bulit** · 05-19-2011

Just did this fix last night during a break in all the rain we are getting. Great right up! Took about 10 minutes to do and cost $3.39.

**Lyael** · 06-10-2011

I tried the "Permanent Fix". I own a 1999 Pontiac Grand Prix GTP 3500. Water on the
passenger side floor board was starting to be a very annoying problem.

I purchased the part at a local Chevy dealership for $3.63 and installed it last Saturday (6/4/2011). After 2 substantial rain storms, the floorboard has remained
totally dry! This was a cheap and very effective fix. Thanks for posting it!

My car has the one-piece cowl, but removing only the passenger side wiper and
bending the cowl toward the windshield made the work area totally accessible.
Removing the plastic flange from the underside cowl was a bit of a challenge because
of the angle that I had to work from. After scoring the plastic with a razor knife,
I used a hacksaw blade and heavy duty pliers to finish removing the plastic. It's
not a difficult repair on cars with a one-piece cowl, but you have to take your
time, be patient and BE CAREFUL WITH THE RAZOR KNIFE!

**brandonl2000** · 06-10-2011

Originally Posted by Lyael

I tried the "Permanent Fix". I own a 1999 Pontiac Grand Prix GTP 3500. Water on the
passenger side floor board was starting to be a very annoying problem.

I purchased the part at a local Chevy dealership for $3.63 and installed it last Saturday (6/4/2011). After 2 substantial rain storms, the floorboard has remained
totally dry! This was a cheap and very effective fix. Thanks for posting it!

My car has the one-piece cowl, but removing only the passenger side wiper and
bending the cowl toward the windshield made the work area totally accessible.
Removing the plastic flange from the underside cowl was a bit of a challenge because
of the angle that I had to work from. After scoring the plastic with a razor knife,
I used a hacksaw blade and heavy duty pliers to finish removing the plastic. It's
not a difficult repair on cars with a one-piece cowl, but you have to take your
time, be patient and BE CAREFUL WITH THE RAZOR KNIFE!

yup. my old GT had the one piece. i just bent up like you did, then i tried cutting on it with a blade and slit my finger. so i ended up just breaking it off with pliars. and it broke off really clean since it was all dry and stuff. worked wonders for my car too.
glad you got a fix.

**Scottydoggs** · 06-10-2011

i went the super cheap way on this last year, i took all the cowls and wiper off on the pass side, and when i got to the bottom part, that you replace, the liner part that fails, i took doubled up thick plastic bag, cut it to size, and stuffed it up into the grove where the old one was, left in there too, and silicone it, also silicone the weather stripping under the first cowl piece too, no leak in almost a year now.

**brandonl2000** · 06-10-2011

the man is a resourceful genius!! ^^

**Scottydoggs** · 06-10-2011

Originally Posted by brandonl2000

the man is a resourceful genius!! ^^

if i were still roofing i would have used epdm rubber roofing to do it, it was all i could think of at the time till the bag came to mind.

epdm is like a rubber tire tube material that you glue up like rubber cement, brush on both side let it dry and press together, it would have lasted the life of the car, but it ain't cheap and didn't have any, so the bag went in.

so i did have a better idea how to fix it but not the supplies. the bag wont last for ever that's for sure.