Got a 98 Chevy Suburban 1500 LT 5.7L. As I was coming home today, I notice my check gauges light came on and the temp was up to around 250. It got warmer, but I putted home.I let it sit and cool off, put 2 gallons of antifreeze in and recranked. It warmed up slowly and then went back up to the red.I cut it off and left it alone. What's wrong with my baby? HELP!