have an 05 explorer overheating took
thermostat out ran good for a few days
started overheating again changed fan ran
good about a month now its overheating
checked head gaskets not blown
Could be a bad water pump. The impeller on the water pump erodes away causing poor circulation. You would have to pull the water pump to check, but this is a common problem. Also the cooling needs to be purged from the air pockets whenever opening up, draining coolant from the system. Another cause you have not mentioned would be a plugged up radiator. A radiator flush would be in order to do, or replace it.