So I have been having problems out of my 4 cylinder TJ. At first I suspected a bad coolant temp sensor. On further inspection I determined my radiator probably needed to be replaced as it looked like it was corroding on the outside and was leaking slightly. I put in an OEM radiator single row... my old radiator was the old two row style... and an OEM thermostat and gasket. Flushed all the brown gunk out of the cooling system and refilled with 50/50 zerex coolant and burped the system. All was well for a day... Jeep ran for a day slightly below 210. Then it started going into the red again. My next step is the water pump but before I change it and get it all back together could my head gasket be blown or maybe even my block be cracked? I have no white smoke from the tail pipe and there isn't any moisture coming out of it either. My jeep also isn't running poorly. I know I should do a compression test but is there any other signs of a blown head gasket that I might have?