Quote Originally Posted by FordMan77 View Post
When was the last time the thermostat was replaced? Maybe it has junk in it too causing it to stick closed. Depending on the condition of the cooling system the rad could be plugged up too. And no, I haven't seen a waterpump leak due to overpressure. Just a bad pump seal or gasket.

Did you briefly open up the screw several times on the thermostat housing while it was running at full temp? It should produce a steady stream of coolant. If it's spitting and hissing then it's still got air in the system. I've had to have the car jacked up in front to get the air out before on a stubborn one.
new when i did WP. flushed system before replacing Wp but could have broke crud loose after.
ran it to the store yesterday in 12 degree weather. catastophic mode kicked in again. coulds of smoke comin out the tail pipe. but then notice other vehicles must have blown head gaskets,too! LOLOLOL
im gonna be pullin it into the shop tomorrow to start investigating.