So earlier today , i was in the drive thru and i noticed white smoke/steam coming from the car . i guess it was steam cuz it dissappeared in the air. the thermostat was on high so i turned off the engine for a bit since the line took a while . then i tried to restart it like 2 minutes later but it wouldnt start . it was stalling . so it wasnt the battery . i saw a bunch of smoke coming from the hood so i popped it . and i opened the water cap thingy . i took a gallon of water i had in my trunk and filled it with half a gallon of water . then all of a sudden steam and hot air blew out of the hole for like 3 minutes . i closed it then i pushed the car in neutral to the parking lot . i waited like 10 minutes . started the car then drove home . but halfway home i heard a bang . but i didnt feel anything on the car and the car was still driving normal . i managed to make it home . there was a little smokecoming from the engine . so i let it cool down . WHat did i do wrong ? or what did i do right ? I have a honda civic coupe 1999 .