I had the same problems and I had to get a new radiator and that fixed it. I'm not saying that you should go out and buy radiator but that's what fixed my carI have a 2001 Intrepid, 3.2. Last year I had the following replaced on the car:
Upper and lower radiator hoses
Radiator (filled with HOAT 50/50 coolant)
Thermostat (Mopar) - not installed backwards
Upper intake gasket
Both cam seals because of oil leak
Water pump not replaced because fairly new, however, the pump o-rings were replaced due to coolant leak
Switched the upper intake from my 3.2 Concorde because the one from the trep in better condition.
After work completed car overheats, but needle moves below halfway when turn on heater. Each time overheated, the system bled until no bubbles.
No loss of coolant and no milky color of inside of oil filler cap, therefore, head gasket likely not blown. Heater blows hot, so likely not caused by a bad heater core.
No air bubbles in coolant at the bleeder port, today. Coolant level in reservoir is consistent. Today, overheated after a 5 minute drive 40 F degrees outside. Upper radiator hose warm, and radiator cold too.
Any ideas as to cause of engine overheating?