94 Roadmaster rust under passenger carpet
when I today lifted off the floor carpet of my RMWagon on the passenger side, I found frightening some brown epidemic on the front RH side in the region of the A-pillar at the doorsill. First i was scared about rust Perforation, but when checking properly it´s not through. Theres a small sheet metal clamp which fixes the cabel channel, this clamp is dissipated by rust and caused a terrible look, but no welding is required, just cleaning, derusting and sealing.
But what I´m much more interested in is the reason of the moisture which might be present for sure. I own the car since 4 weeks now and didn´t move it in traffic at all, but when I took it home for 250 miles I realized a coolant smell inside what disappeared for some time and came back again, maybe quarter-hourly. I`ve heard by some rumours that moisture occuring on Buicks RM/ Chevys Caprice exactly in this area is well known by the experts and the reason can be the heater core or the A/C? Could anyone tell me the reasons and problems to supress this problem? The car is inside stripped down and everything would be nice to get at.
Thanks lot for your help!