Method for the Determination of the Composition of Diesel Engine Piston Deposits by Infrared Spectroscopy

A chemical method for separating diesel engine piston deposits into various organic and inorganic components is described. The components are subsequently analyzed by infrared spectroscopy. The method is illustrated with examples of deposits removed from the upper lands and upper ring grooves of pistons taken from heavy-duty diesel engine tests. Subtle chemical differences were observed between two deposits removed from upper lands of pistons taken from diesel engine tests which had been carried out with the use of lubricating oils with different formulations. More obvious differences were found between the deposits taken from the upper land areas and the upper ring grooves. These results indicate that a combined chemical and spectroscopic approach has the potential to provide detailed chemical information about engine deposits.