So I've noticed my 63 chevy impala with a 350 small block make a strange bubbling noise that sounds like it's the radiator/coolant. At times it'll do this simply by getting in and sitting in the driver seat other times upon going for a drive and getting back home and shutting off the engine. Now I've read it's possibly a blown head gasket but is there any other possibilities? If indeed it is a blown head gasket what other symptoms are there?