ssj2link

iTrader: (15)

so i just got this car, its a 91/92 camaro convertible. i bought the car knowing it had some rust in an odd place, at least to me. the firewall in certain spots has holes in it, some of it is below where the A/C parts would be toward the bottom and there are a few small holes maybe the size of a half dollar right under the relay farm on the driverside. before i go and patch these holes up ( cut them out and weld in new steel ) what could have caused this? this is my third third-gen and also the newest, i had a 90 firebird and i have an 86 trans am, neither of these had the rust this one has. im just curious on where this would have started, i wanna fix that as well as the holes. ill post some pics hopefully tomorrow when i get some pics of it.

nosajwols

iTrader: (1)

On my car the seam sealer in the cowl failed. This let water in between the two layers on the firewall, resulting in rot.

stealtht/a

iTrader: (1)

Rust as you described is pretty typical for cars that sat outside, especially near an ocean. Once the drain in the wiper channel were clogged with leaves or something it all starts too rust.
Personally, bad firewall rust is a deal breaker for me. Too critical structurally to ignore and too integrated to fix easily, I'd prob send it to the crusher.

ssj2link

iTrader: (15)

here is the rust, i would prefer not to crush it as i can simply weld in new pieces of steel.

LX_SS

Its easily repaired, replace the entire firewall if you have too.
The downside is there is going to be a lot more rust than what you can see in the pictures.
Strip all the areas, find out exactly how bad and proceed from there, Even if you have to cut out half the firewall to replace it, not too bad a job and allows you to do some smoothing or heater box mods and such whilst your at it.
Stealtht/a is correct in leaves/debris being the cause, especially in the first picture, add some rain and moisture soaking in.
Other causes are the internal flap housing for the air inlet direction of the heater, when leaves go in the drain channel, this fills up with water completely, pretty nasty.

ssj2link

iTrader: (15)

thank you guys very much! ill be looking into this on the weekend

Mirror Image

iTrader: (2)

Yeah I would have to agree that is a easy fix first I would get the rust off the right side to see just how bad it is it looks to be pitted but if it hasnt gone through just get all the rust out and epoxy prime and repaint and on the left side I would look on the inside and see how it is in there if the same as the outside I would cut me a patch panel clean off all the rust and weld it in and be done

nosajwols

iTrader: (1)

Check the floors as well, this type of rust usually ends up in water collecting under the carpet (trapped in the jute)--it did on mine.