no i don't think it's the head gasket, i had the same problem with my s14, it is the air bubbles and the thermostats, but you have to find that air hole screw to let out all the air, then unblock that button on the bottom of your radiator to let out all the water, coolant, and then put the plug back in and tighten the air hole, then refill with water and coolant. Unless your car is smoking hella bad then it's not the head gasket. It could be your water pump too, or it could be your thermostats, sometimes autozone or advance auto parts sell bad ones.