Coolant gremlin

[Nutz]

I have 01 f250 with 7.3 psd 110000 mi. After driving about 5 mi. my heater started blowing cold air, the temp gauge went up to just below red, puked about a pint of coolant. Within 1 minute everything went back to normal, heater blowing heat, temp about halfway on gauge. Drove 40 mi. at highway speeds never any problems. It has done this 3 times now same thing. Everything back to normal by the time I get the hood popped. It has lost heat a couple times going to work ( short 5-6 mile drive) but temp guage never goes over halfway and doesn't even reach that due to short drive, But still let it idle once at work and nothing out the ordinary. What the fuhell please any info I appreciate it

[Nutz]

Well if anybody cares it doesn't seem to be a headgasket. Was told possibly injector cup. Sometimes they split inside the head and allow pressure into coolant, and can cause irregular overheat spells because they tend to seal themselves temporarily. After passing a block test though, it seems that my problem is because I apparently can't fill my overflow to full, because if I do I have the problem mentioned above. Haven't topped off coolant and is doing fine so far........