tama. try to get a second opinion. kung cylinder head gasket lang yung initial problem, dapat madali lang naayos nung mekaniko. nung unang beses niya pinalitan yung gasket, dapat na check na muna niya yung head at yung block for warping (binkong). madali lang naman i check yan for warping. mahabang metal ruler lang malalaman mo na.

if the problem persists, mali yung pagkakagawa nung mekaniko.

btw, wala ba leak ang radiator mo? baka dun ang leak.