My 1994 jeep cherokee 4.0L inline 6 at idle for ten minutes reaches 260F I have a new radiator, water pump, thermostat, heater core valve, and new valve cover Gasket, I have a new heater core and oil pump but have not put them in yet. I do not have oil in my radiator fluid nor do I have water on my oil dip stick so I concluded that it is not a head Gasket, but the little electric fan does not stay on when the vehicle reaches this temp nor does the radiator feel hot I would think that the radiator would feel hot since water boils at 212F. I just have water circulating through the system now for I wanted to make sure I had no leaks in the system, did not want to waste money on Antifreeze/Coolant until I checked everything that is new first, will remove bottom hose when I find out what is causing this excessive heat in the engine. Anyone with feed back on this would be greatly appreciated