AN INVESTIGATION OF THE RELATIONSHIP BETWEEN USED ENGINE OIL PROPERTIES AND SIMULATED INTAKE VALVE DEPOSITS

The degradation of engine oil and its influence on the formation of in take valve deposits is being discussed in this paper. Degraded samples of oil were prepared using a stationary engine testbed while depositi on studies were performed using a bench top simulator. The degree of d egradation, as indicated by the amount of polymeric, oxidized and oxid ative products, increases as the engine oil is used over a period of t ime. The rate of degradation, however, varies depending on the quality of base oil and the type of additives used. It was observed that the degraded oil played an important role in the formation of inlet valve deposits.