Been having a problem with my truck lately, the temp gauge will go from 1/4 to all the way up the hot it will stay there for a few seconds then go back down the the middle area. The truck will have no heat untill it goes back the the middle area. There was some coolant coming out the the degas container so I replaced the cap on it and had and even worse problem. I drove the truck about 2 miles with the new cap, the temp gauge went all the way up and stayed there the whole time, the hot engine collant/oil pressure light came on and so did the the service engine soon light. The truck also went into limp mode.

I donot think it is a headgasket because it is not losing coolant, and it is not smoking nor does the exhaust smell like coolant. Could it be a thermostat or a water pump? the truck has 82,000mi on it.

 

The motor is overheating due to loss of cooling flow.
Could be the thermostat or even a plugged radiator.
I would consider replacing the thermostat and checking the radiator for flow.
It comes out quite easy.
Might as well do both and include new coolant of the correct type for FORD use, at the mileage you have.
The faults you saw happening are normal from poor cooling.
The heater is the highest point in the cooling system and will loose coolant first as coolant level goes down and steam is produced, there will be no heat.
Good luck..

 

I hope its just a thermostat. I took it back out for a drive the motor went to half way on the temp gauge then shot up the high, after 30 seconds it rapidly went back down to half way and ran fine for 15 mins, heat coming out of the vents and all.

 

You have a cooling problem that as to be repaired.
Hope you don't operate on hope and a wish and get into the repair and clear it up so it's not an ongoing hassle.
Good luck.