2002 Mercury Mountaineer Overheating engine

Engine Cooling problem
2002 Mercury Mountaineer 6 cyl All Wheel Drive Automatic

My vehicle constantly runs hot. I have replaced the radiator, thermostat, water pump, and checked all the fans and it is still running hot. There is no water pressure coming to the thermostat. When I remove the thermostat there is no water there. When I start it up and put coolant in it, the water comes up to the thermostat. Then when I run it, it starts running hot again. I have replaced everything that has anything to do with the cooling system. There seems to be no water coming up to the thermostat like it should. I have checked the hoses and the water pump again and the hoses aren't collapsing and the water pump is fine. What could be causing this?

My vehicle constantly runs hot. I have replaced the radiator, thermostat, water pump, and checked all the fans and it is still running hot. There is no water pressure coming to the thermostat. When I remove the thermostat there is no water there. When I start it up and put coolant in it, the water comes up to the thermostat. Then when I run it, it starts running hot again. I have replaced everything that has anything to do with the cooling system. There seems to be no water coming up to the thermostat like it should. I have checked the hoses and the water pump again and the hoses aren't collapsing and the water pump is fine and the radiator has been checked. We realize that the heating hose is causing pressure to build up. Once the pressure is let off it stops running hot for about a week then does it again. What could be causing this? How can it be repaired?