A new technique for detecting antifreeze in engine oil during early stage of leakage

摘要

The oil condition sensor and sensing algorithm invented at Delphi Corporation can detect un-dispersed antifreeze, which appears as a separate phase and settles at the bottom due to its higher density. In order to detect un-dispersed antifreeze, the sensor has to be mounted at the bottom of the oil pan. An earlier version of this sensor was not capable of detecting antifreeze existing in engine oil during early stage of leakage or before the phase separation. This work demonstrates that the changes of engine oil resistance should enable us to detect antifreeze during the early stage at a concentration of 0.5% for used engine oil or as low as 0.25% for fresh oil. An algorithm could thus be developed and added to the oil condition sensing algorithm. This add-on feature would not only offer more flexibility in mounting the sensor, but it would also enable the sensor to send out warning signals during early stage of antifreeze leakage.