Well after doing some reading here, it seems like alot of others have had the same problem as me. I have a 99 ford ranger that is my daily driver. 3.0 motor. When i start the truck in the morning i let it warm up for a minute or so, then take off. As i get about 2 miles up the road, the temperature guage shoots up from zero to halfway (normal temp) in a matter of 3 seconds. At that point the heat will blow cold. As i get about 2 more miles the temp guage will drop back down to the cold line. At that point the heat will start blowing warm air. Now as i drive to work (about a 25 min ride) the temp guage will go up down up down up down, and the heat will blow hot cold hot cold hot cold. By the time i get to work its pretty steady temp and blowing warm air. When the truck runs, fluid bubbles into my overflow bottle to the piont where it will fill all the way to the top and push the top off. I have replaced the water pump, thermostat 2x, both radiator hoses, radiator, and radiator cap. Also bypassed the heater core to make sure that that wasnt clogged. So by all this i have determined that i have a blown head gasket and or warped/cracked head. Im going to start pulling it down tomorrow. Im pretty decent at working on cars but ive never tore into this motor before. Anything to be aware of, or be carful with? Or things that have to come off in a certain order? Any tips, tricks or info you could give be would be much appreciated.