We were contacted by a superintendent of a livestock carrier who had recently taken charge of a vessel fitted with a QMI Oil Mist Detection System. During a steady voyage, the Oil Mist Detection System indicated a high Oil Mist reading in one of the crank spaces. The engine was stopped and investigations made, but no main bearing damage or bearing temperature difference was identified.
The engine was restarted, and the Oil Mist reading increased again on the same unit. Upon further investigation, the piston ring set was found to be badly damaged and the high Oil Mist reading was caused by combustion gases reaching the crank case