ok i have an 88 dodge caravan the heater went out so no heat drove it anyways noticed steam coming out of vents and a bit of water thought all this was cause of heater core it was my only means of transportation so i had to drive it i didnt think it was a big deal .. so now it started to bubble and now it over heats drove it around the block started to bubble so i let it cool down and added warm water started it and boiled over again what could be the problem or problems.. any ideas... things to check ???? thanx bell