The Contribution of Engine Oil to Diesel Exhaust Particulate Emissions

A radioactive tracer technique was developed to determine the contribution of oil from an engine sump to exhaust particulate matter collected on a filter. The technique was applied to particulate emissions produced by an automotive diesel engine which was operated on an engine dynamometer over a range of steady-state conditions. The results indicated that from 1.5 to 25 mass percent of the particulate matter, depending on speed and load, consisted of material from the engine oil. The oil contribution to the extractable organic portion of the particulate matter ranged between 16 and 80 percent.