Well here is another post about my ongoing cooling system problem. I thought I fixed it with a new radiator but I still have the same problem. The truck runs great on the freeway uphills and all, no signs of overheating. I drove 250 miles yesterday with no issues. When I get off the freeway it heats up until I get moving again. This sounds like a fan clutch what has got me is the coolant overflow bottle gets so full that it overflows and I lose some coolant. I think this is why I am getting the above normal temp. readings. It seems like it is getting too much pressure. Do the bypass hoses do anything like this? I just used regular hose so they are kinked. What else could it be. I have been thinking headgasket but I really am hoping it is something else. The exhaust doesn't smell and the oil and coolant don't show signs of cross contamination.