[JL8Jeff]

I don't know 3rd gens well enough, but I'm assuming it has electric fans. Did you check to make sure the fans are spinning the right direction when they are turned on? Make sure they are pulling air through the radiator and not pushing it from the engine compartment forward. If somebody messed with the wiring maybe they could have reversed them by accident. Other than no coolant circulating, you really shouldn't have a reason for it to start to overheat just sitting there if the fans are working right.