I wonder if the grille shutter might not be opening as designed.
This Jeep is equipped with active grille shutters, it is located at the bottom of the grille (see diagram below). The purpose is to keep that area closed to improve fuel efficiency, but open when the engine needs cooling to improve air flow through the radiator.
It is possible that the shutter is stuck closed, due to the actuator being faulty.
So even if the radiator ran turns on in high it is just not getting enough air through.
Images (Click to enlarge)
Saturday, October 16th, 2021 AT 2:41 PM