91 4Runner

Hey, my guitar teacher has a '91 4runner and apparently the radiator is rusting out and this is creating holes in the piping, and i live in Idaho so there is no problem with excessive humidity (seems more like negative humidity most times..) and there is no salt in the air.
is this a typical problem with the 22re engine?

Not that I'm aware of, but if the coolant hasn't been changed often enough, or tap water or well water has been used in the coolant instead of distilled or deionized water, you will have trouble with any radiator.