Car is overheating

I had the same problem. I replaced the water pump, radiator, thermostat, & the bottom "t" hose, plus new coolent. Turn the car on over flow right away. After many hours of trying to keep the coolent in I figured out I had an air pocket in the heater core, because no coolent was reaching there. No heat in the cab of the car. So I pulled the heater hose off the thermostat hosing, put my garden hose on the heater hose hole & filled it up. Problem sovled.
I f you have a blown head gasket and the hole is small you can get away with radiator stop leak for awhile, it happend to me and it lasted for years good luck

have you changed the thermostat, and bled the system? it may have a vapour lock,
worst senario, head gasket , blocked radiator or water pump

you are not going to like the answer, but it sounds like you have a blow head gasket. To check to see take out the oil dip stick, and if the oil look like a chocolate milk shake then that it the problem, so you would have to take it to a shop, thats a big job.

Check and see if the Thermastat is stuck closed.