no idea. are you sure it isn't just circumstantial?

when in 4wd, you're usually going a lot slower, which means less airflow through the radiator which could exaggerate cooling problems. I suppose 4wd puts slightly more load on the engine/driveline, but not anywhere near enough to really effect engine temps. otherwise, 4wd and the tcase have absolutely nothing to do with your vehicles cooling system.

can you reproduce the symptons every time just by shifting the 4wd lever? how long does it take after shifting in for temps to start rising? do you have any problems with temps rising in 2wd during slow parking lot type conditions (sub 15mph)?



-Rob