Heating

Hello mechanics thanks for the good work. I drive a 1kz engine that recently overheat and burnt the gasket. We changed gasket, piston rings, piece bearings, serviced cylinder head but the heating just cant go away, there are bubbles from radiator and it coolant dries up so fast without visible leakage. But, there was a visible crack inside the block where pistons sit but my mechanic told me its minor, and also he says its my radiator that needs replacement, if so where does my coolant disappear? Please help because this car feeds my little family down here in Uganda(karamoja). Peace be with you.