It has been several months since you posted this, did it solve the problem? We are looking at a PT Cruiser for my daughter right now and would like to know that these mystery overheating issues can be fixed.
Okay, I found the problem with the over heating issue. After reading most all post here, I concluded that the problem is with the fan motor on the radiator fan itself. I had a hunch that the motor ran on carbon brushes so, I took the motor apart and sure enough carbon brushes. I just so happened to have some carbon brushes on hand so I soldered them in place and cleaned the motor contact point of the carbon brushes. What is happening is, when to much carbon builds up over time on the coiled copper wirering the current flowing over the wire is greatly reduced thus causing an interference with the operation of the motor itself. I simply used a can of carburetor spray to help remove any carbon dust left behind on the motor. My pt is running cooler than ever now. A/C also improved. With that said, I do not believe that Chrysler is at fault here. Carbon brushes are like brakes on a car; they wear out and need replaced in time. Simply and easy fix is to purchase a replacement motor for the fan blades. Should not cost any more than $120. Mine only cost me time.