Although I can see inside the car through this rust hole, it doesn't open up directly to the other side. Does the cowl drain down past this spot? This is a 68 Newport
What causes this rust spot on the firewall?
- Thread starter WissaMan
- Start date
bigmoparjeff
Senior Member
Very common problem on '65-'68 C bodies.
Yes, water that comes in through the cowl vent comes past that spot. Usually when it has rusted through, the cause was a build up of leaves and or dirt in the cowl.
Jeff
Yes, water that comes in through the cowl vent comes past that spot. Usually when it has rusted through, the cause was a build up of leaves and or dirt in the cowl.
Jeff
bigmoparjeff
Senior Member
The really bad ones will also be rotted under the wiper motor.
Jeff
Jeff
Does this mean there is still debris in the vent? Is there a way to clean it out without removing the HVAC system? I have the same issue on my 67' Imperial.
bigmoparjeff
Senior Member
The best approach would be to remove the cowl panel and spray the inside with a hose. It takes about a half hour or so to remove the cowl panel.
Jeff
When I look up under the dash I can see the firewall on the interior-side doesn't look like it was painted at all so I wonder if these spots got much paint, if any.
After clearing the leaves and gunk, maybe something like this would be good insurance against future corrosion: Eastwood Internal Frame Coating Aerosol Spray (14-oz.) Though if there are already holes on the interior-side of the car, you could have a real mess on your hands if you don't mask them before spraying this stuff -- it's kind of runny, not sticky like undercoating spray...
After clearing the leaves and gunk, maybe something like this would be good insurance against future corrosion: Eastwood Internal Frame Coating Aerosol Spray (14-oz.) Though if there are already holes on the interior-side of the car, you could have a real mess on your hands if you don't mask them before spraying this stuff -- it's kind of runny, not sticky like undercoating spray...
mr. fix it
Old Man with a Hat
As mentioned previously, My Polara had a crap load of leaves and dirt in the vent channels. I used a wire to help clean out from underneath even after vacuuming the vent channels out from top to bottom.
Not a problem anymore, I don't keep the car in a place where leaves can infiltrate as well as shooting some Rust check spray down each side.
Not a problem anymore, I don't keep the car in a place where leaves can infiltrate as well as shooting some Rust check spray down each side.
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