Internal combustion engine

A method of operating an internal combustion engine, the method comprising:

• determining, via one or more sensors, a rotation speed, an injection timing, an injection amount, a water temperature, and a fuel temperature of the internal combustion engine;
• determining a nozzle heat receiving amount of an injector and a nozzle tip temperature of the injector, based on the rotation speed, the injection timing, the injection amount, the water temperature, and the fuel temperature of the internal combustion engine, at a point in time when ignition is turned off;
• and
• determining the occurrence or non-occurrence of dew condensation in a tip portion of a nozzle based on the nozzle heat receiving amount and the nozzle tip temperature of the injector at the point in time when ignition is turned off.