Ok so the other day i was doing my whole system so i had the car on so it doesnt kill the battery. And im in the trunk working with the amps and i go in the car(the car has been on for a GOOD while) and i look at the meter and it was like 95% all the way up, close to the H so i hurry and turn off the car and let it cool down. Recently it had been smoking a bit, and i thought it was the valve seals or something i dunno. I turn on the car an hour later its fine, and it doesnt smoke or NOTHING. So yesterday im at a friends house and i open the hood and the coolant resovoir(which was full of coolant) was gone. I thought SHIT i blew my head gasket, but the car is running perfect, no smoke no nothing. So i filled it up with water and so far so good i have to check it soon see if the water disappears. Anyone have ideas, is my engine ok? It only has about 106k miles. Im thinking maybe the coolant just evaporated or something. What do you think??