Any mechanics out there? My truck is overheating in zero degree weather. I warmed it up and went a mile from home ... the heat went cold and the temp pegged out at 260 plus. I can't find any leaks. I don't think the thermostat is sticking because the heater core sounded like it's "gurgling" a bit. I thought something might be frozen in a hose or connection but this did the same thing recently after I was driving for 20-30 minutes ... but it went back to normal and was fine the rest of the way home. Any suggestions? P.S. It took about 1/2 to 1 gallon of anti-freeze. (if it comes in 2 gallon containers).