This last weekend I took the family camping. The mountain we climbed is 8 miles long and about 3000' in elevation. 01 Cummins (33x12.50x18 2" lelveling kit) pulling about a 9000 lbs fifth wheel. As westated up the hill the Cummins started heating up very quickly (over 215). I pulled over, putthe truck into neutral and held herat about 2200 rpm's the temp gauge then decreased back to 190. Long story short, ithappened again this time the check gauge light came on and I couldn't pull over right then. WhenI finally pulled over the temp gauge hit 240 for about a minute. I again put her in neutral and held her at 2500 rpm's &she cooled quickly. I popped the hood to see what was going on & there was no signsof problems.The antifreeze was not boiling or spilling out of the over flow. What temp does antifreeze boil over?Does anyone know why my truck would heat up like that? Bad thermostat?If the water pump is bad wouldn't it leak out the weep hole? Maybe some type of sending unit gone bad? Shouldn't the truck be able to pull that load up that kind of incline? How doI know if the turbo goes out? Shouln'tI be able to hear the torque converter kick in? How wouldI know if that goes bad? (AC was turned off)

 

Don't know about all that, but one way to help cool an engine when you can't pull over is toturn the heater on. If you add the a/c condenser, (leave temp on hot), you have a second "radiator" in which to cool the tempature down.

 

Could be if your torque converter was not locking up, your transmission fluid was causing your temperatures to raise. When you stoped you took the load off ofthe transmision and the temps went down. Just a thought, you may want to have your transmission looked at.I pulled a 9500lb trailler across I40 in New Mexico about 85 to 90 mph and my temp guage stayed at 200 the whole time.

Hope this helps

 

im guessing about the termostat that stay close,that kind of climb is whath those truck crave for

 

Towing 9K 5th wheel trailer with 33x12.50x18 tires and 2 inch lift on your truck and up a 5% or 6% 8 mile long grade, no wonder it got hot. Even if you had only 5K 5th wheel trailer I can see it doing so if you tried to stay at the posted speed limit.