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

I'm going to say probably, since it's a W-body car. The piece itself is not that expensive, so you won't be out much if it doesn't fit. Maybe you'll get lucky and the dealership will have it already in stock, so you can ask if you can check fitment before leaving the lot.

Or just pop the hood, remove the stock cowl and take a look at the area and compare to pics in this write-up to make sure it's the same style.

I've read several pages but havent come across anyone talking about the 2005+ Grand Prix's. I have 2007 GP and after big rains water comes in under the passenger floor mat. I believe it to be the same problem but wondered if anyone with a newer grand prix has found this to be thesame problem for their leaks.

Originally Posted by Burley117

I've read several pages but havent come across anyone talking about the 2005+ Grand Prix's.

I believe it was noted that this part is originally from the '04+ GP's.

Finally got MY permanent fix: HAD THE WINSHIELD RE-INSTALLED PROPERLY!

Mine had one already and still leaks

sorry to bring the thread back from the dead, but i bought the part installed, and i still have water in on the floor board. i cant seem to find where it's comming from. any ideas???

Have someone pour water on the car and see if its really coming from the HVAC case. A sunroof leak can go to the same spot, down through the pillar.

I didnt see any wet spots around the side of the floor board. Just on the floor its self.

Hole in the floor, coming from underneath?

didnt see anything

Originally Posted by 1996pontiac

I didnt see any wet spots around the side of the floor board. Just on the floor its self.

pull the carpet up on the pass front, then have a hose run over the windshield, if its leaking there it will run down the floor/foot board by the hvac fan and box.

my car has a extra layer of floor covering at the furthest away and up towards the ac fan box. it lifts up and will be wet under it if it leaked.

in the pass side floor is a rubber plug, if thats missing the foam under the rug can get wet as well.

It's going to take two people to track it down - one inside the car and one with a hose outside spraying in all the locations that it could leak in - when the intake vent is, if there's a moon roof, anywhere around the door if the rubber is old, or from underneath the car. I think those the the usual suspects for a water leak.

Originally Posted by Scottydoggs

pull the carpet up on the pass front, then have a hose run over the windshield, if its leaking there it will run down the floor/foot board by the hvac fan and box.

my car has a extra layer of floor covering at the furthest away and up towards the ac fan box. it lifts up and will be wet under it if it leaked.

in the pass side floor is a rubber plug, if thats missing the foam under the rug can get wet as well.

Would i still have to pull the carpet up to see if the plug is missing, or can i find it under the car?

you should be able to see it, when the plug is out you can see the ground from inside the car.

but to pull up the rug all you have to do is pull the door sill trim and the kick panel trim, un hook the loops and pull it towards the seat. this will let you see if water is coming down the inside of the fire wall. with a hose flowing down the windshield.

scottydoggs, i will see what i can find out this weekend

I just added this water deflector in as a preventative measure today, and thought some notes of my experience might be helpful for anyone else thinking of doing this:

• 1. If you're doing it in cold weather (in the high 30s today here), be careful you don't break off the little clips that hold the washer line hose in place. The cold seemed to make the plastic extra brittle. They can snap if you put just an ounce too much pressure in the wrong place. Ask me how I know that...
• 2. I turned the little push-pull plastic screw-thingys that retain the cowl into spaghetti trying to pry them off. (It was like they are made of putty.) Only one out of three is reusable. A panel removal tool is now on my "need to have it" list.
• 3. The wiper arms were a !@#$%^&* to get off! Got the retaining nuts off easily enough, but I had to take a small crowbar to the arms to get them to come up! Be extra super careful when you're trying to doing this, however you're doing it. Once I got the cowl off, I saw how close I was prying to the edge of the windshield underneath. A half inch closer and I probably would have cracked it and added the cost of new glass to the $4 part I was installing... I must be missing something because these should NOT be that hard to get off!
• 4. Since I have a 1998 GP, I had to remove the extra part near the blower motor to get the new deflector cover to sit all the way down. It just pulled right out, so that wasn't any big deal. This step was already noted a long time ago; just adding my confirmation that it needs to come out.
• 5. Once the extra rubber and plastic flange are removed from the bottom of the cowl, everything went back together smoothly. Took a while to reset the wiper ams in the right parked position, but once that was done I could relax. Now all I have to do is get two more of those push-pull plastic screw-thingys that hold the cowl and replace the ones I.. um..."persuaded" to come out...
• 6. I'm glad I did this mod, but it was a lot more work than I originally thought. Be prepared to wrestle with it a bit to make it see things your way.

ummm yeah you really over-worked yourself! lol

no need to pull the wiper blades off. just get them in an upward position, turn the car off.
and then there's the argument that your cowl piece is ONE piece. sure. but it's got enough flex in it that you can install it by just lifting it up. so you really just did more work than you had to. and im not sure what you had to remove to get the cowl piece to sit in there aside from pos stock rubber and the plastic that you break off of the cowl.

but good job