Serious interior water leak

[Chillin014]

What are the most common areas for rain water to leak in? I replaced my windshield thinking the seal or crack was allowing water in but that was not the problem. Everytime it rains my passenger floor carpet gets soaked, sometimes even PUDDLING up. I know its coming from somewhere behind the dash but I can't really see the firewall below all the A/C stuff in the engine bay. Does water leak in THROUGH the a/c air duct/cowl area?

All behind the glove box it feels wet. I need to fix this asap as it is raining daily around here this time of year.

I appreciate any help!

 

[chevyman454]

open the hood and see if there are rust spots in the corners near the widshieldif there are leaves and crap un there clear them out

 

[Peter]

my cutlass does the same thing everyo nce in a while. im not really sure why it doesn't happen every rain but when it happens for me it all stays on the passenger floor mat and none gets into the carpet so it doesn't really hurt my car. my impression is that it may be the heater core and i would like to fix mine as well

 

[Chillin014]

Nope no rust near the windshield, we inspected that area a good bit when I had it replaced last week. I also know its not the heater core.

I will take a picture of the area I think its coming from but it's hard to believe that this much water would seep through this location.

 

[Chillin014]

 

[cdg1984]

Mine will leak right around the door hinge area. Look at your door panel and see if you can see any evidence of water trickling down it.

 

[86Olds442]

The most common thing to leak water onto the passenger floor, in my experience, is where the a/c heater box cover mates up to the firewall. Underneath the chrome trim for the wiperblades you will see where I'm talking about. The original sealant might have dried out, or somebody replaced a heater core and failed to reseal it. Its very hard to see where it would leak by looking at it, but it does leak there often.

Hope this helps.

 

[houndin101]

you know where the water drains off your windshield on the pass side....well unscrew that chicken wire stuff look down in the hole and check for cracks....i jus fixed this probleb...if you get under the dash look for very fine cracks

 

[FE3X CLONE]

The most common thing to leak water onto the passenger floor, in my experience, is where the a/c heater box cover mates up to the firewall.

Bingo! That's a good place to start.

After I replaced the heater core in my mom's '88 CSCB she ended up with a leak on her passenger side floor. I pulled the top off the HVAC stuff under the hood again and put strips of 3M weather stripping material on the sealing surface and then once the cover was back in place, along its top edge. Hasn't leaked since.

The 3M stuff is just like what the factory used. It's a very soft type of rubber/puddy that you can form with your hands and contour it around anything.

 

[axisg]

Start top to bottom. Gbodies tend to leak on the PS side because there are so many openings. So look in these areas:

- behind the reveal strip ( chrome or black ) where the wiper blades park at the base of the windshield the cars tend to rot/leak.

Next if you remove the inner wheelwell on the PS you can get a much better look at the airbox and the condition of the firewall around it.

Once you have the wheelwell out you will see a small flap on the bottom of the airbox. Stick you fingers into that flap and see if the way is clear. Leaves, dirt and debris tend to build up and block the flow of rainwater which will push the water into your car.

As well there will be 2 grommets just below that drainage flap. In my case the grommet used for the CCC wires was enlarged to allow for a heavy + wire ( for my amps ) and never reinstalled correctly allowing water into my car.

Again with the wheelwell out check the seam around the airbox where it mounts to the firewall. These are notorious for leaking ( even when the cars were new ). A good cleaning and a bead of windshield sealer / butyl tape ( silicone will rot the metal over time ) around the airbox will usually cure the bad seal.

Lastly just below the airbox is the seam where the firewall meets the floorboards. The caulking tends to get brittle and falls out in this area allowing moisture ( rust ) to form and rotting out the floors.

Start all of this by pulling your front seats and carpet. This will give you a good excuse to powerwash the carpets and hang them to dry.

With no carpets in the car take a hose and run it over the PS area and see if you can pinpoint where the water is coming in.

Good luck !