I have 1997 Frtlnr with 6 speed and 3126. Even at under 26,000 pounds it also tends to run hot. There are probably others that have that same problem.
About that check engine light of yours that comes on. I just had the same problem and had horrible experience at Freightliner dealers in Monroe, MI; Toledo, OH and Youngstown, OH. I limped back to Detroit and went to the CAT dealer in Novi. I wasted 2 days at the Freightliner dealers and about $1,000. I have been to 6 Freightliner dealers in the past 2 years and can say that I thought I was treated right only by the one in St. Louis, MO.
The problem with my truck was the computer, which was replaced 3 months ago and the check engine light has stayed off. The CAT dealer was expensive, and it took a few days, but they did the job right.
I wanted to ask you about the conversion of the FL70 to the RV camper and gooseneck. Did you buy it that way or did you have the conversion done? I am interested in seeing what that would cost.
Thanks, Larry