I have been having a problem with my 2002 F250 Super Duty 4x4. It started about 2 months ago. I was in traffic (truck hadn't even been on for 15 minutes). The temp gauge spiked, so I pulled over and turned the truck off. I turned the ignition on and the gauge was normal so I started it and all was fine.




Fast forward a little and every so often about every 3 weeks it would overflow (coolant) but not get to the point that it would overheat. I changed the thermostat and all seemed good to go. Fast forward to yesterday morning. Got in the truck and left to go hunting, and I didn't even make it 10 minutes down the road when I turned the heat on and it blew cold. I started to see the gauge creep up so I pulled over and shut it down. Upper hose was cold, lower is cold and both heater hoses are cold. After some time of waiting, I started it but the gauge kept creeping up and no heat, so I kept shutting it down. After about 5x of this, the heat worked and the upper hose got hot and all was right with the world. SO I drove it home. Coolant is new, flushed about a month ago and was running great since then. Thermostat is new. Do I have a blockage somewhere? Water pump bad?


I need ideas? Thanks, new to the forum.

 

I was thinking air pocket, but wouldn't think those would just appear in a closed and sealed system that was fine. Blocked heater core wouldn't cause this, especially since both hoses are cold (in and out). Kind of just leaning toward poor or no circulation of coolant. There doesn't appear to be any movement in to the overflow.

 

Welcome!

How many miles are on the truck? A water pump could be a likely culprit or a clogged radiator.

 

off the top of my head, about 70,000. Took the thermostat out to test for flow. Nothing.

 

All seems to right with the world (for now). The water pump was easy to put in, taking about 1 hour of my time and $65 (pump, coolant). The heat works too. Initially there was a really bad air pocket that took forever to get out. Now I am throwing a P0305 (misfire cylinder 5) and P0316 (misfire prior to 1000 rpm). Cylinder 5 is located right next to the thermostat housing, so I would guess some got down in the ignition boot and screwed things up a bit. I would guess the other code has something to do with this as well.