Overheating problems

I have a 2000 mazda 626 that has been overheating.I have replaced the radiator hose’s ,the radiator,the temperature sending unit,the thermostat,and the radiator cap.when the car is a idle it’s fine,but when i drive it for about tem min it starts to overheat.But the car does not so any signs of being hot no smoking no nothing.it does lose the heat in side the car and i felt the heater core hose and they were both cold.i can see that the water is circulation but it does burp up air bubbles sometimes. i think that there might be a air bubble in the system. can someone please help ?

There should be a coolant bleeding process for your car. I do not have a service manual for your car, but having one could seriously help you. Especially if your going to do your own work.