Engine oil viscosity detection method and engine

The invention discloses an engine oil viscosity detection method and an engine, which relate to the technical field of engine detection. The method comprises the steps of S1, after a whole vehicle runs for a period of time, reading running parameters of an engine at the preset rotating speed, S2, determining that the state of a supercharger of the engine is normal and the performance state of the whole machine is normal according to the operating parameters, S3, after the engine is reduced to the idle speed and stably operates for a period of time, determining that the rotating speed of the supercharger is normal, and recording the rotating speed of the supercharger at the moment as the first rotating speed, S4, reducing the engine from the idle speed to the rotating speed of 0, recording the time T1, the engine oil temperature and the environment temperature at the moment, and recording the rotating speed of the supercharger as a second rotating speed, and S5, recording time T2 for reducing the rotating spee