Big Leak--Where is it Coming From? - First Generation Forum

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Big Leak--Where is it Coming From?
Tuesday, October 04, 2016 11:11 AM
For most of the summer, I noticed a sort of musty smell when I was in my car. I couldnít find anything and was trying to figure it out when about six weeks ago, I saw the front passenger side floor was soaked. I figured this must be a symptom of those cowl drains being clogged and didnít worry about it since I was about to put new fenders on the car.

Well I cleaned those drains and thought my problems were over. I even went through a car wash to make sure it would stay dry. Then last night, I found the front passenger side soaked again! This morning when I got to work, I figured since I cleaned the drains already, I should check the back. Well the back floor on the passenger side was even more soaked.

I canít figure out where the water is coming in. My floor pans look great from underneath (wouldnít pass inspection if there were holes), and everything seems dry above the floor.

My door seals seem fine, and the flip-out window seal also seems to be OK. I know the moonroof leaks, but if thatís where it was coming from, I would think my headliner would be soaked as well.

Is it possible it is somehow coming through the flip out window, and staying inside the paneling, running on the outside of the paneling between the passenger compartment and the inside of the quarter panel, then draining onto the back seat floor?

I didnít get to fully check the trunk, but will check more as soon as I can, but could it be coming from there? Is there a known issue like this that someone could tell me?

Re: Big Leak--Where is it Coming From?
Tuesday, October 04, 2016 10:33 PM
Wayne let me do some checking before I comment.I did some book work (shop manual) but not what I am searching to verify to tell you.I feel confident I have the answer but,I need to verify my thoughts before I do so.I doubt the doors or side windows are the problem or cowl area with the rain trays or even wiper motor mounting.I will follow up on this wed.I have delt with a similar issue with my nephews old 98 accord and fixed that with the same problem.

Re: Big Leak--Where is it Coming From?
Sunday, October 09, 2016 6:28 AM
That's a tough one Wayne.

I would try removing the inside panels (kick and door sill for starters) and pulling back the carpet as far as you can. Then put a hose on the car and with a light try to see where the water is coming in.
Might be easier to remove the front passenger seat to get better access.

Let us know.

Re: Big Leak--Where is it Coming From?
Sunday, October 09, 2016 10:34 AM
My 88 had a leak I couldn't find. It was water getting in behind the door sill seals at the A Pillar and running down inside the seal until it got to the about midway along the bottom where it would drip out into the floor.
I had everything out of the interior and one day when it was raining steady, I went out and sat there. I soon found it. I pulled the seal off, caulked it and replaced it, no more leak.

These pictures show the general locations of where the water was getting in behind the seal (Leak Entry) and where it would come out into the cabin (Leak Exit).
Leak Exit.jpg (106k)
Leak Entry.jpg (506k)

Re: Big Leak--Where is it Coming From?
Monday, October 10, 2016 8:29 PM
I second pulling the seat and do a carpet pull back and hose it down to narrow the issue.I would have suggested the heater core grommets but I really doubt that as it is centered in the firewall.I assume you have a aftermarket sunroof correct?If so there would not be any drains just a seal.

Re: Big Leak--Where is it Coming From?
Monday, October 10, 2016 9:03 PM
Check the spare tire well. My 89 and my 94 both filled with water. I had to pump them out.

On the inside my car looks like a fighter jet.
Re: Big Leak--Where is it Coming From?
Tuesday, October 18, 2016 11:38 AM
My 86 leaks onto the passenger floorboard, this drove me insane! I could see water dripping outside of the car when my air conditioner was running so I thought that it was not leaking into the passenger floorboard until I pulled the carpet back and noticed that somehow the condensation from the air conditioner was getting through the seal to the firewall I have taken it apart four times and put it back together and can not get it to stop leaking into the floorboard on the passenger side. Again if you look outside the car most of it is going out of the drain tube for the air conditioner, but the other condensation for some reason is dripping behind the AC condenser and getting in between the firewall and the sponge seal that separate them, the seal fills up like a sponge and if I squeeze it with my fingers the water just rings out of it and it all runs to the passanger side floor board. Just a thought for you Wayne hope you solve your problem.
Re: Big Leak--Where is it Coming From?
Sunday, January 29, 2017 5:13 PM
My old '92 Z-24 had a firewall rusted so badly that it literally split the firewall laterally down the middle.
The PO let 8 metric tons of pine needles fill the area of the cowl where the wiper motor sets.
It was so bad, I had to get rid of the car....

~ Mike ~

Re: Big Leak--Where is it Coming From?
Monday, January 30, 2017 1:09 PM
My 86 had the same issue. It had a small split in the metal cowl under the wiper area. I filled it with epoxy and problem solved.
Re: Big Leak--Where is it Coming From?
Monday, January 30, 2017 1:14 PM
Well, safe to say I'm ripping up the carpet this year and will probably use clear calking around the weatherstripping as I think it's coming through the passenger door somewhere. Then of course, I'll need a new carpet and have to learn about putting that in...yippie!
Re: Big Leak--Where is it Coming From?
Monday, February 20, 2017 1:44 PM
So after all the wonderfully bad weather I've had, I had a nice puddle on the rear passenger side. Took the car to a friend's house and used a shop vac to get out a bunch of water.

In my driveway, the car is typically parked facing on an uphill grade (very slight, but it's still an uphill grade).

At my friends house, it was on a very slight downhill grade.

While there, water was coming out the bottom of the car from the front passenger side floorpan.

Is there some sort of drainage I should know about in the design of the floor, or do I have a new and bigger problem?

Re: Big Leak--Where is it Coming From?
Saturday, February 25, 2017 3:36 PM
Hi Wayne

There are a couple of places water can legitimately be coming from under there. Each side has a couple of removable plates that can rot out and leak 1st. These are from my Wagon on the passenger side. You might get lucky and have them go on you 1st but as always the rust gremlin will do his best to ruin your day.


Re: Big Leak--Where is it Coming From?
Sunday, February 26, 2017 6:25 AM
Just to make sure I got this right:

those removable plates don't form a full seal, and therefore, my water is supposed to (or simply will) drain out when parked on a downhill grade if the massive puddle is located on the rear part of the floor pan.

That sure makes me feel better about it, I do plan to rip up the carpet this year (guess I need to hunt down a new carpet--I'll go with black), and I now park my car the other way in the driveway so it can drain if necessary.

Just to summarize the thread:

I don't think it's coming from the firewall as all the wetness is on the floor and only slightly higher. Just thinking if it was at the firewall, even when parked on the uphill grade, the wetness would be much higher than just on the floor. All the wetness seems to be below the bottom of the door level, or to say, the leak has got to be from the door. I really think Butch has hit the nail on the head here with the problem, although the actual spots on entry/exit could be slightly different.

So, I have to ask--would I be able to use clear calking all around my weatherstripping to solve this, or must I remove and replace the weatherstripping? The rubber all really looks good, so I would hate to do that if I can just use the clear calk method.
Re: Big Leak--Where is it Coming From?
Sunday, February 26, 2017 6:49 AM
Unless they have been tampered with, they are sealed at the factory.

The Feds would never let a car maker sell anything with a floor pan that wasn't airtight.

It would be worth the trouble to get this car up on a lift for a proper inspection - then you would know what you are dealing with under there. If the floor pan is rotted away , you are in trouble. Constant moisture under that carpet is gasoline on a fire. I had a similar problem on my 86 Ranger, and finally ripped out the carpet. Cleaned everything up and layed down 4 coats of Rustoleum and 2 coats of Cool Seal. Of course it is an old Truck, but it solved my issue so well, I have left the carpet out of it ever since.

My advice is to get the car up and see if you still have a floor pan under there, then rip out that carpet ASAP. Once out you will find out very quick where that leak is coming from. Everyday with that carpet staying soaked is just ravaging your floorboard. If it isn't rotted away, it will be.


Re: Big Leak--Where is it Coming From?
Sunday, February 26, 2017 4:31 PM
That's the weirdest part--the pans look great under the car.
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