My truck is running hot. It seems that is has been doing this almost since it was new. My stepfather bought it new and has paperwork saying that it has this problem, and they replaced the pump and did a full check. I recently had a radiator flush done, and it did nothing. Under normal driving it is not a lot hotter than it should be, but when I am towing or sitting in traffic it heats up huge. Last time I took it out with the trailer it almost went to the red. We had to slow way down to like 55 and turn on the heater to get it cooled even a bit. My tech says it is not anything he can tell, and the only advice I am getting now is to rod it or replace it. Is there any other advice that I can get.