i mean best case scenario its just condensation that is building up in the exhaust, which means is not a big deal, naturally happens. blown head gasket means ya need a new one or your going to cause big damage. i think if you run either the a/c or heat, not sure which one, it can ruin your chances of salvaging whats left. i would check in with others that post on here. thats just my basic knowledge so if im off by others accords, believe them not me lol