1992 passat 2.0 overheating

[763dad]

I got the car in december 09 with no heat.Replace a broken heater core and then a thermostat.Then temp light kept flashing,took it to the dealer every thing check out.They said replace the evpo tank so i did.It had some heat,then in april when got hot out outside anti boil out of the evpo tank.I pulled the water pump it is metal ,rad flow tested,pulled the head and had it check nothing,block is not warp.Found under the head gasket on the block on number 4 white mark from water jacket to the cyclinder,can not find out why.Never use anti or smoke,it ran fine.I am not sure if in want spend the money to put it back together or sell it?