Hey guys need second opinion. Today my 1982 Monte Carlo 305in radiator coolant jug started boiling and spitting out all the water and antifreeze. I check radiator and its not leaking. I parked it let it cool off and added more water and coolant. When I was driving home the engine start rattling and loosing power. Didnt think it would make it home. By the time I drove 10 minutes home the coolant jug was boiling over again. I hope its not blown head gasket or something serious with the engine. YOUR THOUGHTS!!!
If there is no visible leaks, finish your driving for today, and have it cool down for 5-6 hours if you haven't so already.
Then turn on the heat on the dash and fans as much you can, and take off your radiator cap. Start the car for 30 mins or so, and every 5 min rev the 305 up, while squeezing the top rad hose gently.
After throw on the rad cap, shut the motor down and drive it once things have cooled down aight.
If it still boils, replace your stat and repeat my steps. Only after that if no change then see about flushing rad and heater core.