new one for me. wife went to work car over heated, limped home. later i checked the tank and empty. filled up with water and put cap back on. stated up fine, ran for a while, turned on the ac and didn't hear fan kick on. temp still looked ok and thought its cool out today, maybe it wasn't warm enough yet. put the car in gear, needle started to rise. car is running and i popped the hood hoping to see a coolant leak and right as i went back to turn ac off the cap blew off and a coolant volcano flowed out the front! crazy!! lasted about 10 seconds! covered the whole engine! never seen a cap just blow off!! HELP!!!