A New Methodology for On Line Oil Dilution Measurement

On-line measurement of oil dilution is of particular interest in light of new environmental regulations imposed on today's high-performance engines. In particular, after-treatment devices such as diesel particle filters (DPF) need to be periodically re-generated in order to eliminate their soot content. Such re-generation process is usually performed by using post-injection cycles that can induce a transfer of fuel to the lubricant, resulting in oil dilution. Anew method was recently developed by DSi sprl and Total France for monitoring oil dilution on running engines. It is based on lubricant labelling using a new radiotracer compound, which is stable and representative of the oil distillation interval. Measurements are performed by circulating the engine oil to a measuring chamber where dilution is monitored. The method was recently applied to gasoline and diesel engines where dilution results have proven to be accurate and repeatable. These results are compared to those obtained using a conventional method: gas chromatography (GC).