[rdlamb]

Ouch, Art, I was answering the newbie's question, and I am not incorrect in any of my statements.

First, checking with Cummins, my temperature gauge is correct. My engine fluctuates very little, and does stay around 165, pulling a mountain or roaring the plains. This is just above the 1/4 mark on my gauge.
I cannot hear my Aux fans when they come on, so I do not know how often they run. But, my engine temp just does not vary.

Second, the posted question's author noted their engine was running on the hot side, 1/2 to 3/4, which I took to mean a gauge pointing well past the right of center. That being the case, I stand firm that the individual should contact their dealer, or Freightliner, or the engine's manufacturer (I do not know what engine the Newbie has in his TM). Something seems amiss.

Finally, overheating a diesel is one of the few things that can greatly hurt the engine. Water in the fuel being another. I still strongly recommend an immediate consultation to diagnose the problem.

Finally, check the radiator, make sure you have the proper amount of coolant in your tank. I like to keep mine just below the max line, but well above the minimum line.