I just bought a 97 honda civic a few weeks ago...wish I hadnt...I am familiar with mechanics but am just stumped when my civic began randomly one day, to heat up really fast while travelling at any speeds, then suddenly cool down to regular running temperature, It repeats this. My fluid stays full at idle (unsure about after travel I cant check without burning myself), and the fan kicks in like it should. I changed my rad cap, and topped up my rad coolant (50/50 mixture) Also before I changed my rad cap, the rad would spew coolant everywhere (it did this for while but I never had overheating problems) Im hoping my water pump isnt buggered, im almost 100% sure theres nothing wrong with the thermostat. Could my radiator be under pressure or maybe an air bubble in the system? My oil isnt milky, and my exhaust is regular. Please help I drive for a living...