INTERNAL COMBUSTION CONTROL METHOD AND INTERNAL COMBUSTION CONTROL DEVICE

An internal combustion engine control method controls an internal combustion engine equipped with an exhaust gas temperature variation factor unit that varies the temperature of an exhaust gas of the internal combustion engine, an exhaust heat recovery device disposed in an exhaust passage downstream of the exhaust gas temperature variation factor unit and that recovers the heat from the exhaust gas into a refrigerant that cools the internal combustion engine, and a refrigerant flow rate adjustment unit that adjusts a flow rate of the refrigerant that passes through the exhaust heat recovery device. The internal combustion engine control method estimates a boiling margin, which is a parameter related to a thermal margin when the refrigerant boils in the exhaust heat recovery device, and determines whether to execute a boiling avoidance process in accordance with the boiling margin.