Can't find the source of interior leak

Tiny
DGRIFFIN123
  • 1999 PONTIAC GRAND AM
  • 120,000 MILES

I have a 99 pontiac grand am, and the rear passenger floor is always totally soaked. I really don't see where it comes in from. There doesn't seem to be any leaks from the door at all, and from what I can see theres nowhere underneath the car that it could be coming from. Also, my driveway is on an incline if that makes any difference.

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Tuesday, January 10th, 2012 AT 8:20 PM

17 Replies

Tiny
DGRIFFIN123
  • MEMBER

Also, my trunk has water problems as well. It had several inches of water in it at one point, the spare tire was totally underwater, so I punched a small hole in the bottom of the trunk to let the water drain out.

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Tuesday, January 10th, 2012 AT 8:24 PM
Tiny
FIXITMR
  • MEMBER

Some have reported the spoiler mounts in trunk? Someone also suggested door is not draining properly and then overspilling into car.

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Tuesday, January 10th, 2012 AT 8:40 PM
Tiny
FIXITMR
  • MEMBER

And this was reported. All Pontiac grand prix from 1999-2009 that leak water on passenger floor is from the following: The front cowl panel, [Where windshield wipers are] Has a air box inside the panel, That when built has a two piece construction that is sandwiched together at factory, and over time, summer heat, Icy winters etc, dries out and allows water to get into air box and drip out below dash on passenger side. To fix: Remove wiper arms, remove cowl screen, and you will notice a box looking square on passenger side, Clean out in and around box opening top. Must be clean and dry. Next use ether urethane windshield sealant, or silicone water proof sealer. Reseal all the way around box, [Where metal body meets air box.] Make sure to re seal all the way around air box and let dry overnite. You can buy ether sealants at your local automotive parts co.

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Tuesday, January 10th, 2012 AT 8:42 PM
Tiny
DGRIFFIN123
  • MEMBER

Awesome, I'm gonna go check that out right now. Thank you for the quick reply!

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Tuesday, January 10th, 2012 AT 8:46 PM
Tiny
CADIEMAN
  • MEMBER

It comes from the front cowl area. Open the hood and look for any lose rubber gromets on the firewall. Remove the under dash panels then pull the carpet back on both sides. Which side is wet by the firewall?It leaks in and rolls back to the rear behind the front seats. Have a helper spray down the firewall. You stay inside and look for waterleaking in. These leaks maybe from a split seam also. Remove the trunk carpet then get in the trunk with a flashlight. Let your helper flood the trunk out. You should see no light coming through anywhere. Check the l and r trunk hinge area. Then check for a leak at the wheatherstrip. Youll find them keep looking. Youll need to strip out the interior to dry the carpet to get rid of that smell.

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Saturday, January 21st, 2012 AT 7:17 PM
Tiny
NICK KLEINTZ
  • MEMBER

For the trunk leak on the pass side in trunk remove carpet and you will see a flapper valve thing seal it! And for back seat floor theres a plug in the floor that probally came loose just go under car and seal that as well. Hope that helps ya!

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Wednesday, January 4th, 2017 AT 9:53 AM
Tiny
2CARPROS KEN
  • ADMIN
  • 4,973 POSTS

Hey,

Great addition to this thread! Please feel free to help out on the site whenever it can add information that will help people.

Best, Ken

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Monday, January 9th, 2017 AT 12:24 PM
Tiny
T.H
  • 1997 PONTIAC GRAND AM
  • MERGED

Interior problem
1997 Pontiac Grand Am 4 cyl Front Wheel Drive Automatic 150000 miles

When I bought my 1997 Grand Am Gt I noticed underneath the floor mats was damp. I was told that there is a seal inbetween the window and windsheild wipers, and water seeps through there. How can I fix this leak? If that is where it is coming from.

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Monday, January 9th, 2017 AT 12:24 PM
Tiny
BMRFIXIT
  • EXPERT
  • 19,529 POSTS
  • MERGED

If the windshield that is leaking than best to remove windshield and reseal it
glass shop is your best bet

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Monday, January 9th, 2017 AT 12:24 PM
Tiny
IAMSICKOFMYPONTIAC
  • 1997 PONTIAC GRAND AMPONTIAC GRAND AM
  • MERGED

1997 Pontiac grand Am Grand Am GT v6 137,000 miles. Recently I have noticed that the floor underneath my driverside floor mats is wet. I had this problem about 8 months ago and I had the mnifold gasket repaired along with the heater core, but now it seems the problem has continued. I recently checked this becasue as I went to get my oil changed last week, the said my coolant was very low, so I checked the floor and it was wet, could it be the water pump? I really do not know, but I would like to have an idea of what it is so that when I go an have it looked at I know whats going on, what do you think it is and about how much will it cost? For the time being should I just keep an eye on the coolant level and keep filling it up until I can get to a mechanic? THANKS

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Monday, January 9th, 2017 AT 12:24 PM

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