I have problem with the cooling system. Its not working. I have replaced the raidiator, water pump both hoses and the thermostat, i have also replaced the pressure cap on the the pressure tank. i’ve checked the the oil for a possible head gasket leak and still it over heats. I have ran it with and without the thermostat, i have by passed the the heater core and i have even removed the upper hose to make sure that there is flow. i need help . Its a v-6 4.0l with 167,000 miles
Define “overheat.” Does it boil over, or are you going by the dashboard gauge only. Have you replaced the coolant temperature sensor? Is the cooling fan clutch (if applicable) working? Could there be something blocking airflow through the new radiator?
[b]There are different types of head gasket leaks.
Some introduce coolant into the oil without the engine overheating, and some cause the engine to overheat without introducing coolant into the oil. You may have the latter where combustion gasses are entering the cooling system causing the engine to overheat.
Remove the radiator cap and start the engine. Now observe the coolant in the radiator as the engine runs. If you see bubbles forming in the coolant in the radiator, it indicates a breach between one of the cylinder firing rings on the head gasket into a coolant passage in one of the heads.