2002 Sport Trac with about 140K miles. We bought this used about 2 years ago and have had multiple issues with it including changing cat converter, fuel pump. This is a bit of a long story but I will try to keep it as short as possible but also supply all information. Not sure how much of this might be related.

About a year ago it started running bad; stalling, stumbling, dieing, etc. In and out of shops about 5 times with no resolution. I changed plugs and various sensors with no luck. Also, about this time, the heater core started leaking. Took it to local shop to swap heater core. Still having the drive-ability problems so we did not drive too much. Finally, local Ford dealership put in a new PCM/computer, Driving mostly better but did stall and stumble a few times. They tweaked the computer settings and it drives 99% better. Now it is overheating. Mostly when it is about 90 or hotter which is quite often in Tampa. Changed thermostat twice. No water or any other leaks. Normally the tamp gauge is at the bottom of the thermometer picture and was like that for several years till this started. Now it climbs almost all the way to the "H" mark. The "Check Gage" light will even come on. If we shut off the A/C the temp will stay way high for 5 to 15 minutes and then slowly drop towards the top of the thermometer. But not any lower. Whether going down the highway at 55 or 70 or driving in traffic it does the same thing. If the outside temp is below 85 it tends to NOT overheat. I have tried to purge all air by pumping the top radiator hose. Coolant level is good. Heater blows hot. I can feel VERY hot air blowing from radiator towards the engine. Holding my hand as close as safely possible, I can feel extremely hot air blowing from radiator. So hot I can't hold it there comfortably. I also changed both sensors on top of thermostat housing.

This one has me stumped! Thanks for any thoughts.
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