Tuesday, August 14th, 2018 AT 10:54 AM
Van started overheating had Ford replace water pump. Lasted fifty miles. Started over heating again. Replaced thermo and both up and low radiator hoses still overheats. Seems like air trapped in system. Was road testing with scanner reading coolant temperature heater was on high heat coolant temperature 212f air coming from dash hot then all of the sudden temperature shot to 234f and air from dash went cold. Three minutes passed and it reversed back ro 212f and hot air it did this about six times. I got home and shut it off. This morning the reservoir is full and under pressure prior to the coolant level was spot on. Earlier did block test no exhaust gas in coolant. Did pressure test held 20osi for twenty minutes. Any idea what could be the problem? Forty five years of diy and in lost. Help!