W.E.G.

Trying to figure out the source of the water intrusion on the '88 Camaro.

I lifted this screen-thingy up as far as I dared without disconnecting the washer-fluid lines.
The flexible washer-fluid lines look just old enough that if I pull them off the fittings, I'll have to replace them to get them to ever work again.

Where does the area under the screen-thingy drain?

I peered in there as best I could with a flashlight, and while trying to get a viewpoint around the screen-thingy. I can't see where it drains.

Should I consider this area a possible suspect for the water intrusion?

I'm getting water intrusion just from it sitting outside. I don't have to drive it to cause the intrusion.
The water appears on the driver's side front floorboard. Quite a bit of it.
So far, I'm stumped as to where its getting in.

shake401k

Ive added a tsb that i found on alldata that relates to your issue, im not sure specifically where it drains out tho,

Jersey89GTA

iTrader: (1)

Pour some blue windshield washer fluid in there and see if it shows up inside the car - kinda like a tracer. -or see where it comes out.

xbleedblackx

It drains out underneath the car

nosajwols

iTrader: (1)

The main drain is on the passenger side behind (underneath) the fender. The cowl slopes that way and there is a rubber flap on it.

One issue I had on mine was that there are at least two layers of steel on portions of the firewall. The seem sealer failed and water was getting between the two layers and rotted them out making a new drain(s) from the cowl to the interior.

6SIX6

iTrader: (35)

Like nosajwols says thats exactly the way it goes. For it to come in the driver side it might be coming in from around the windshield as well. Water is a tricky thing to figure out where its coming from

Maverick H1L

iTrader: (8)

The cowl drains on BOTH sides of the car, but the main drain is on the passenger's side behind the fender. If you don't have A/C, there is the possibility that the gasket for the fresh air vent on the driver's side has failed. Best thing to do is to pull the driver's side hush panel (if you have one, some didn't) and look up at the bottom of the cowl to see if you can spot a rust hole or perhaps a water drop that hasn't dripped yet. May also be a rust hole behind the fender plastic. Primary problem is that there are something like 4-6 sheet metal components that all come together at the bottom corners of the cowl. I'm having a problem with a leak on the passenger's side, for which I'm going to have to pull the fender off again and run a bead of seam sealer as far across the cowl as possible.

micktroup2

I had a similar problem on my previous 3rd gen. It turned out that the car had rusted through where the floor of that chamber you are looking down on meets the firewall underneath the brake booster and towards the drivers side, of the firewall. The previous owner had plugged it with bondo and painted over it.
Run a magnet over the firewall in front of the driver to see if you have a similar repair. Then pull the driver's side hush panel as advised and start checking. Have someone pour some water into the cowl drain while you are under there...

W.E.G.

Helpful info.

Thanks!

BTW, I do have some firewall rust issues.

6SIX6

iTrader: (35)

If thats the seam then you might have a hole for sure

nosajwols

iTrader: (1)

I had similar rust. I repaired mine with some welded in patches where the metal was really gone. I also removed all the seem sealer in the cowl, I had the entire cowl empty, no vents, no heater box, no wiper assembly... I then pored chassis saver into the seem (entire length, we made a wand sprayer) and it ran out any of the remaining pin holes inside the car, once dried the holes are filled and the panels are super bonded together. Then I re-seem sealed the entire inside of the cowl.

bobs

iTrader: (2)

Just so happens I have both my fenders off. I have attached a few pictures. Drains from the passenger side behind the fender. No such drain on the drivers side. (Edit) There is a smaller 1" by 2" hole in the frame structure on the drivers side though.

W.E.G.

@ nosajwols

I'm very interested in your experience removing the wiper assembly.

Any pitfalls I should consider?

I'm leery about disconnecting the existing wiper-fluid lines. I realize now that these lines are integral to the wiper arms. It appears that if I bugger the lines at all, I'll be buying new wiper arms just so I can get the washer-fluid lines.

You mention pouring Chassis Saver into the seams. Any thoughts on Chassis Saver vs. POR-15? One good as the other for this repair?

Did you pull your dash assembly out to get at the firewall, or did you attack the entire project from outside the cabin?

W.E.G.

@ bobs

Thanks for the pics and the detail about the drain locations!

micktroup2

There's your problem! Looks like you have rusted through where the floor of the cowl vent is welded to the firewall. If you want to do a permanent repair, you may have to pull your dash and entire interior and or fenders and engine bay, because we may be talking major plastic surgery here. I am talking 'Kardashian'! If you don't get that rust out, it will continue to rot away and open up more holes and problems.
If it is anything like mine- fortunately a fire consumed the car before I had to put more money into it(!)- I could see you having to cut open the entire cowl, rebuilding the floor of it and then welding the cowl roof and firewall back in. Which means your interior will have to be out of the way. One of the real vulnerabilities of third gens...

W.E.G.

More awesomeness from the 1Aauto.com guys.

Good vid on the cowl-drainage question.
Discussion at 3:16 in the vid.

nosajwols

iTrader: (1)

We had the interior completely stripped. I do not remember any real drama in removing the wiper etc. but my car is an 82 the sprayers are cowl mounted on mine and completely separate from the wiper arm assemblies. We also did this at the same time to deal with the top side....

https://www.thirdgen.org/forums/fabr...-progress.html

We used chassis saver since we could get it at the local body supplier. I have heard the two are pretty much the same but I have not tried POR15.

W.E.G.

That thread is absolutely THE BEST thing I have found on the internet on the subject of dealing with cowl/firewall leaks on third-gen.
THANK YOU!

That improves my perspective greatly on where I need to go with this repair.

Did you end up painting-over the carbon-fiber?

Since you inundated the carbon-fiber with all those epoxy-products, why not just use the much-more-inexpensive (and easier to get) fiberglass cloth instead?

W.E.G.

After looking at that thread again, I think I answered my own question.

If I understand correctly, the epoxy-inundated carbon-fiber was not painted over.
The look is quite good.
Is the epoxy coating on the carbon fiber it holding up to the elements well?
Any signs of the epoxy starting to get cloudy?

Were you having any firewall leaks with this car?
Seems to me if the horizontal cowl-piece had rust-pocks, you would have holes at the base of the cowl drain too. (Which is what I suspect I have, and which is what I believe is the cause of the water intrusion that is collecting on my front floorboard.)

nosajwols

iTrader: (1)

Some quick answers...

The car is STILL... in the rebuild phase so it has not seen the elements yet. We used epoxy that was UV "inhibited" and clear coated the entire cowl with two stage paint clear coat so I am not expecting any issues.

My firewall was much worse than yours and it was leaking in many places (inside and out). We welded in quite a few patches. Firewall was rotted out (large holes) near the wiper motor, below the electrical main connector and below the heater box, all was replaced with new metal--plus the chassis saver between the panels for the pin holes.

Here is a progress pic with windshield in. We used stainless screws for the wiper mounts.

zapped83

try to look under the brake boosteto see if there is any hole one way is to put a trouble light under the booster and look from underneath the dash to see if there is light coming through or you might have to pull the fender of to see if there is any rot around the door hinges or the pillar and make sure you pull off the fender liner so you can get a better look let me know how it works out hopefully this helps and yes don't forget to check around the windshield.

W.E.G.

Pulled the cowl-screen loose again today.

Ran straightened coat hanger down both sides for cowl drains.

Encountered wet obstructions on each side.

A little ram-rodding with the coat hanger seemed to punch the obstructions.

Will be working on it more in the coming week.

Looking forward to the arrival of the new dash cover, so I can pull out that crazy thing that's on there now, and start working on getting a look at the backside of the firewall.

Maverick H1L

iTrader: (8)

Don't just worry about under the cowl screen and dash. Remove the kick panels and look back there as well.

I've noticed several areas that like to rust:

1. At the bottom of the kick panels, under the carpet. This usually comes with a hole in the floor pan at the rocker panels under the car as well. Caused by the constant assault of water/rocks/salt/etc on the metal in this area by the wheels. There is also a spot where the rockers are folded over in several ways during the stamping process. I've noticed that, in these spots, it looks like GM never put seam sealer or SOMETHING there to prevent water from getting in.
2. The area down below the lower door hinges. And next to the harness pass-through on the passenger's side. Don't know why.
3. Some point along the cowl seam. Because the factory uses seam sealer that hardens over the years, which cracks and allows water to seep in and sit.
4. The rear side of the passenger's wheel well. Right above the area where the panel is flat and has an "X" in it. Probably the same reason as #1. Don't know why the passenger's well and not the driver's, but both of my F-bodies have had rust in this area, the 88 worse than the 87.
5. Driver's foot well floor pan. Self explanatory. Water gets in there because of snow, mud, wet feet, and/or any of the above.
6. Small areas around the rear wheel wells. Small spots become big problems.
7. Spare tire compartment floor.
8. Floor plugs in the rear corners (inner sides of the stowage compartment and spare well at the bottom of each) like to rust out. Don't know why there either.
9. Battery tray that's actually holding the battery. Self explanatory. Not much help available for those having the battery on the driver's side, however.

You may not have rust in any of these areas, but you may want to look anyways. If you're not sure where water is coming in the cowl, get out a hose and run it into the cowl. You'll find where the water is coming from REAL quick.

And you won't be able to see the back of the bulkhead without pulling the entire dash, HVAC box, pedal set, and insulation underneath. Just isn't possible with pulling only the dash pad.

W.E.G.

Great checklist!

I'll be going over all those areas.

Well... maybe not the battery tray. Its way up front on the passenger side. It has plenty of issues of its own, but allowing water into the cabin is probably not one of them.

(view of battery tray looking up from underneath the car)