questions:
a: is the fan coming on, if not then your thermo switch is bad.
b: is the lower radiator hose hot after the car warms up...if it is not, then your thermostat is stuck closed.
c: how many miles are on this car, and when is the last time the thermostat was changed?
d: how does the radiator itself look, is there any buildup, excessive bent fins, bent or crimped coolant passages?