if the thread starter mentioned he usually checks his coolant level daily, then probably the silicone seating of his radiator cap is probably busted and corroded due to dirty radiator. In other words, it cannot keep the cooling system pressurized thus it loses a lot of coolant, hence, the overheat. IMHO, it is best for him to have his radiator cleaned, his engine block water galley undergo lavramon, change his radiator cap with a new one, recharge his fan clutch with silicone oil and finally a 50:50 or 60:40 distilled H2O-coolant mixture