Engine is overheating;
> checked fluids, water boils into the overflow tank after shut off and white smoke coming out of the blow by tube. I assume a bliwn head/gasket or engine? Engine shuts off at idle when hot.
Sounds like you may have a blown head gasket but still need to find out why it is overheating. I would check the thermostat at this point. Also make sure the radiator fins are clean.