widglid96

I have a 2004 f-150 with the 4.6 v8, a little history about this truck, during the summer we had a bad over heating problem with this truck, while running down the road temp was fine but when at stop lights etc. the temp would climb up, had system flushed and filled, still got hot, noticed overflow/expansion tank not draining, cleaned tank and found antifreeze low , filled it up and things seemed fine, now that it is cold , no heat? checked fluid level it seemed ok, once again overflow/expansion tank dose not seem to be working, fluid level in tank never changes, after running truck down the highway and temp gauge reads it at normal operating temp, upper radiator hose is warm but not hot along with the upper heater hose. fluid level in overflow/expansion tank is at the mark, when engine is cold fluid level is the same. im thinking the cap on tank needs replacing, not getting a vacuum and air in system, maybe hole tank? Chrysler had this same closed system on there Cherokee in the 90's ,it sucked big time and the tank was usually the problem. I ended up replacing system with an radiator with a cap.any idea's?

techrep

iTrader: (1)

Need to check both heater hoses.. inlet and outlet hoses need to be hot at operating temp with full heat selected in cab...if the inlet is hot and not the outlet .. your heater core is either clogged or your blend control is not working. If both just warm .. circulation problem.. T stat or air in system.