The main requirement of engine lubrication oil is to lessen the wear on the engine parts, reduces corrosion, clean, improves sealing and also to reduce the heat from the engine. If this oil is not frequently changed, dirt and sludge can develop on the engine and this old and impure oil won't properly lubricate the engine moving parts such like new lubrication oil does. Dirty oil can cause the serious damage, and if it continues as bad enough, it can be even an engine replacement happens in the near forthcoming period. The scope of this review article is to discuss various methods of detecting the degradation of engine oil by various methods in detail.