Is your coolant disappearing but not showing up in your oil? Mine was small crack it was burning off before it got to serious, also check your head gasket, dry head at high temp tend to cook these.
Does your exhaust smell sweet?
Pull your plugs, are they really clean?
If yes to either of these its either the head or head gasket, you can see it in the head by pulling the valve cover, chocolate milk color under there at all SWAP IT
Head gasket, is a bear to get to, but a good learning experience. If you have to swap the head, PM me I can help you threw some of it (as i just did mine)