I had just changed the thermostat and the water pump........i stilll overheat and still hear a hissing sound somewherenear the heater hose....if thats what it is that goes into the water pump.....its above the water pump whatever it is.....i cant drive the truck and its something that i hope is an easy fix.......its a 99 dakota v8 slt magnum.:banghead:

Something must be blocking the flow somewhere, have it flushed under pressure.