Engine oil analysis is becoming one of the core subjects for Condition monitoring of the Diesel engines. During engine operation, Lubricating oils are used to lubricate the engine, and hence they serve as the lifeblood of the Diesel engines. During lubrication, a considerable amount of worn metal particles from the engine's moving parts moves and settle in the oil and contaminate it. Therefore, a lubricating oil flowing cyclically in a Diesel engine carries much information about the working condition of the engine parts. The contaminants in the oil indicate the health of Diesel engines. Oil properties like corrosion, oxidisability and pollution content can be diagnosed by different physiochemical parameters such as total acid number (TAN), viscidity, total base number (TBN), water content, etc.