I have a 2009 4X4, 4.0 XLT. I recently shipped it from Hawaii to Seattle, and upon arriving the truck had no heat. Heater worked fine ( when needed) in Hawaii. Heater control valve works, changed thermostat, and bled coolant system. There is a very slight amount of heat on the vent setting. The engine also surges when holding at 3000 RPM. Put in a 192 thermostat, and gauge sits straight up. I'm baffled.

 

sounds like a blend door issue. It controls the mixture of heat/cool when you turn the temp **** the fact that your getting a little kinda sorta eliminates a cooling system malfunction id start by pulling the radio bezel and see if you can move the door by hand and get heat.

 

Thanks, I'll give it a try.

 

blend door unit sits on tpo of heater behind glove compartment pita to get to (3 screws on top of it to remove) good threads on here to look at. just take your time

 

To bad FORD didn't have the wisdom to make the GB door removable.

 

Hard to make them removable it can be worse. I have done a newer buick that required complete dash removal to replace it had 12 hours labor just to get to it so all in all these are not bad.

 

When you drained the coolant did you run water through the heater outlet? You can get an attachment with a coolant flush kit at walmart, you splice into the heater outlet hose, hook up your garden hose and run the water. This worked great for me, you wouldn't believe all the crap that came out of the heater core.