i went through all that your going through and the man was right ,check to see if you still have an air dam thats probably your problem

 

One Thing He Didn't Mention Was If He Is Losing Water. A Small Crack In The Head Gasket Can Cause Overheating With Only Minimal Water Loss. One Sign That Might Be The Problem Would Be White Build Up On A Spark Plug Tip Where There Is None On Any Of The Others. Sick

 

I HAD AN OVERHEATING PROBLEM ON MY 89 CHECK THE HEADS MINE WAS MORE EVIDENT AT FIRST START UP WITH WHITE SMOKE BUT TO CONFIRM WICH YOU CAN DO WHAT SICK HAS SUGGESTED WITH THE PLUGS

 

another ting to think about is the cooling fan relay, they go bad all the time.. If the one fan isn't working at all and the secondary kicks on only with the ac.. this might be the issue