I solved the over heating problem with out 02 Journey by installing a new radiator. Of course yours isn't that old yet but the core can become corroded inside and plugged up.
Now I have all the power I need with no heating at all no matter what I'm climbing.
Jim and Carol Cooper with Oreo the Kitty
FAA ATC ret, VFW, AL, VVA, NRA
US Army Aviation, MACV Vietnam 65-66
2002 Journey DL 36, 3126 Cat 330hp