[Tf175]

On our trip to Ohio this past weekend , 1500 miles , I saw elevated engine temps on the 8v92 . On the same trip last year it would start going above 190 on longer grades , so I would back off the throttle until the Pyrometer and boost would go down , then temp would stabilize below 210 mark . If speed dropped to 50 , downshifting to 3rd usually did the trick . I should mention that we tow a 28 ft enclosed trailer , probably 10K # load . As the ambient temp went higher this year it was more difficult to keep the engine temp down , started seeing the needle get to 210 and beyond , but never let it get farther than halfway between 210 and 230 marks . At one point we made a quick pit stop and the trans would not shift into drive from neutral , and this happened a couple of times afterwards . I think the trans temp went so high that there was not enough pressure available for the elec/hyd Stone Bennett shifter , but the trans always shifted and pulled well . The relief valve on the water heater even started leaking , I think because the water had been heated to near boiling . On the return trip the situation became worse , had to pull over a couple of times on grades to avoid extreme engine temps . 
  The radiator looks dirty in the corners outside the shroud , I'm thinking cleaning the rad will help this . The radiator sight glass shows full and the reserve tank level is where it normally is cold , although it went up some during trip while hot . I haven't pressure tested cap yet . Oil on the dipstick looks good , hasn't risen , should get it analyzed . I don't see any indicators of engine damage , but I am mindful of overheating horror stories I have read . Looking at ordering a Digi Panel , from posts I have read it is a good system and includes trans temp reading . Not sure if the standard 45' harness will work , or if it needs the extension. 
  I intend to clean the rad , replace at least the upper hoses ( one has a bit of a kink ) and go with fresh coolant . Perhaps the thermostats ? Water pump ? 
More as it goes ,
Thanks,
Chris