My turbo 1000 is running a bit hotter than it used to even in the same ambient tempuratures. It all started one day when it was raining and I figured the loose fan belt tensioner was the prob. Fixed that and it's better but not what it used to be. Idle or low load temps are fine but any real street driving and it goes up to about 100ish on the guage. Before it stayed right at 80 maybe climb a little on a steep grade. I did a full flush. Changed the thermostat and spent over an hour straightening fins on the rad. It also seems to have to cycle a bit before it gets hot. It's fine for the first few minutes of running at temp. I have a couple theories but they may not make sense. First one is radiator cap releasing pressure too early and not allowing air back in creating a slight vacuum that might make the lower hose collapse. Second one is fuel quality. This condition started within minutes of getting fuel and I'm still on that tank. Is that even possible? My third theory is obviously the radiator (what's left!) After I return from the run most of the radiator is warm but not the lower half for about 6 rows in the middle. Clog? Just seems strange that a radiator would clog all of a sudden. I read about the vanes rotting off the water pump. How common is that? Is there a way to check water pump flow without pulling the pump? What is the pressure rating of the stock radiator cap? I'm going to change that and the lower hose along with have the radiator flow tested tomorrow.