i have a 2007 pacifica 4.0 engine and i have no heat. i flushed heater core and oil filter cooler and they seem to be okay. but after refilling the cooling system im noticing the same issue,during further inspection i noticed the top radiator hose was cold and temp gauge was right in the middle. so i replaced the thermostat. NO CHANGE! i have bleed the air from the bleeder by the thermostat and i still feel theres an air lock or???? can anybody give me some pointers

 

If you look in the radiator/coolant bottle (not sure on this engine as it's not in the UK), can you see the water moving? It could be a failed water pump.

Also when filling up, make sure where you are pouring coolant in, is the highest point in the system, you will need to jack the car up in the right place for this, this should help prevent any air getting trapped in the system.

 

i had previously blew out the oil cooler, well even tho it seemed clog free it wasnt. i bypassed it and that fixed it