My 93 Honda Civic was constantly leaking coolant. I replaced the radiator. Today I noticed the leak again. Now I know it could be cracked/blown head/gasket or cracked block. I already checked for coolant in the oil. It was clean so I'm thinking it is a cracked block. Is there another way to make sure it isn't the head? How can I be sure? Is there a way I could do some sort of visual test before I go out an get a new block? Any help would be appreciated! Thanks.