2003 Ram 1500 Overheating / Loosing Coolant

[RoadAF]

Having problems with loosing coolant and overheating (almost). Over the past two months changed: Thermostat x 2, radiator, fan clutch, hoses, pulleys, belt and water pump. Engine starts to heat up and temp goes to about 2 0'clock and then it appears the thermostat opens. Heater does not throw out hot air until the thermostat opens, then fluctuates hot/cool. Temp then remains at 12 o'clock +/-. After driving for about an hour and then letting cool overnight the reservoir is about an inch low. No apparent leaks anywhere. Last week the temp when almost to the red line before the thermostat opened. Being told it may be the heater core. Need some help on this one..

 

[rowdyram]

4.7 v8?

 

[RoadAF]

5.7 V8 Hemi

 

[05singlecabHEMI]

can check your cylinder compression to make sure your head gaskets are okay. next time your do an oil change make sure there is no coolant in the oil.
did you burp out all the air when you put the new coolant in?
did you install the tstat correctly? there should be an air bleeder on it and that needs to be at the 12 o'clock position.

 

[rowdyram]

Those symptoms are definitely head gasket take it to a shop and have a hydrocarbon test done