1998 Expedition engine wont heat up

[Cougar Man]

I'm new to this site, I have a 1998 Expedition, I've had it for almost 3 years, in the last year I've had issues with the heating system. First my daughter drove it to collage last winter and then said she couldn't get it to put out hot air when she drove it, I put in a new thermostat and flushed the coolant and cleaned out the coolant bottle; still couldn't get it to put out heat. I have sence then replaced the water pump due to going bad. Replaced the thermostat twice since then because the engine wont get above 140 degrees, flushed the heater core, and replaced the cap on the coolant bottle because I noticed that it dosent buil psi in the cooling system. I'v checked the blend door under the dash and it opens and closes as it should and the actuator motor works, front and back just fine. After all this, and letting it run for 45 minutes, then driving it for an hour, it still is not building pressure in the system and the heat is still not hot enough inside. Any ideas of what is causing it to not heat to 195 degrees like it should?

 

[Petesexpy]

So, you have good flow through the core but the engine is not heating up, is that the problem? First, did you check if you have good pressure in the outflow hose from the heating core? If hose is stiff, then the only thing I can think of is the incorrect thermostat. I would get one from the dealer just for the heck of it. As an aside, you could have 2 problems - 1. the temp gauge is not working (check the engine temp with the infrared gun) and 2. Your heating system is not working. Did you replace ALL hoses of the heating system? Finally, did you blead the cooling system after all the work you did? it could be an air bubble trapped somewhere.