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Water leak into rear seat floorboards

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Old 12-23-2009, 09:36 PM
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Default Water leak into rear seat floorboards

Hi

99 SSEi


I have searched on this forum and read the many messages about water getting into the car. I have tried lots of things but still my rear floorboards are getting sopping wet after a rain, even when parked on level ground for a few days.

Here are the things I checked and did:
- sunroof drainage holes seem to drain properly
- cleaned out the mud from behind the front wheel wells
- checked the trunk and spare tire storage, no water.
- took off the roof-body drainage channels and reattached them with black auto silicone
- poured water down front cowling.. seems to drain. dunno if water is leaking from there
- door and trunk seals have been cleaned and look ok.
- no water or dampness in roof lining
- seats not wet, also checked behind rear seats
- front floorboards not wet

One thing I did notice was water from the roof drainage channels was pouring into the black vents on the inside of the rear door jamb. I sealed around the black vents with silicone and also made a silicone "deflector" to move water away from the vents and towards the outside of the door jamb.

The wetness seems to appear more near the middle of the floorboards (near the hump) rather than near the doors.

Can someone please help me find this leak?

thanks!
Old 12-23-2009, 09:42 PM
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Passenger side, front seat. Pull the carpet back from the firewall and check for moisture. I'm suspecting your HVAC drain is clogged.
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Old 12-23-2009, 10:53 PM
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You don't mention anything about checking the watershield inside your door trim panels. HVAC is definitely a possible source, but if you haven't pulled your door trim panels and checked to make sure the butyl seal that holds the watershield (large plastic sheet) to the door inner sheet metal is intact, my money would be on that being the source of your leak. The butyl (black sticky chit) tends to dry out and pull away, leaving water a path to travel into the passenger compartment.

Let us know if you need help on how to do this.
Old 12-24-2009, 01:01 AM
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Right rear wheel-well...? Check to see if you have a hole, as it is common.

Last edited by Bonne99; 12-24-2009 at 01:02 AM.
Old 12-24-2009, 12:14 PM
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Look at rear wheel wells, this is what I found in mine. This is my right one.
Attached Thumbnails Water leak into rear seat floorboards-1997-bonneville-rust-005.jpg   Water leak into rear seat floorboards-1997-bonneville-rust-003.jpg  
Old 12-24-2009, 12:15 PM
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I should have mentioned the water gets into your trunk and then runs under the back seat area.
Old 12-24-2009, 03:57 PM
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Thanks everyone for the pointers. I will check those out today.

You don't mention anything about checking the watershield inside your door trim panels. HVAC is definitely a possible source, but if you haven't pulled your door trim panels and checked to make sure the butyl seal that holds the watershield (large plastic sheet) to the door inner sheet metal is intact, my money would be on that being the source of your leak. The butyl (black sticky chit) tends to dry out and pull away, leaving water a path to travel into the passenger compartment.

Let us know if you need help on how to do this.
Are these inside each door? or the plastic rain channels attached to the roof on the car (I've checked those)?. Yes, please tell me how to check that.

Thanks
Old 12-26-2009, 01:11 AM
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Check the metal panels in the floor boards that they are actually secure. Found mine had rotted the tip of steel that held the plate tight to the floor pan and everytime water splashed up it soaked the floor from underneath the carpet. You can check it by just simply pushing upward on the drain panels under the car, there are four of them, 2 rear, 2 front.
Old 12-27-2009, 07:10 PM
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Hi Everyone.

So I pulled back the carpet in the front passenger side, and it was soaked underneath. I cant tell whether the wetness started in the front, or just moved to the front. I have attached some pictures. 1st one is carpet up, some moisture on the "underlay". 2nd pic is the underlay, and it is soaked.

How do I check and clean the HVAC drain? Where is it? I ran the car with the AC on for 10 minutes but didnt see much water coming out underneath the car. Also how to clean the condenser?

Also, what is that control box dangling in the 1st picture, and where is it supposed to attach to?

I checked the wheel wells, no holes or corrosion. Haven't checked the floor panels yet or the door water shields (not sure how to do that).

It looks like I might have to some major drying to get the carpet dry. Do you think I will need to remove the front seats to get the carpet out to dry?

Thanks

matt
Attached Thumbnails Water leak into rear seat floorboards-dscf3170.jpg   Water leak into rear seat floorboards-dscf3175.jpg  
Old 12-27-2009, 07:51 PM
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Ooooh, where getting somewhere! Hopefully you have ramps!? Or a way to raise the front end off the ground. Your going to have to get underneath with a piece of stiff wire and basically clean the chloresterol out of the drain tube. Looking at your blower motor, below that and to the left. Which would be the passenger side, is a small tube about 2 inches long and hangs down from the airduct area. I'll try and find a picture....
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