Patent ID: 6449538
Filing Date: 2002-09-10
Classification: F01M

Abstract:
An engine oil degradation detector that works out a use level of an engine oil in accordance with a driving manner of the internal combustion engine, the use level of the engine oil indicating how much the engine oil in an internal combustion engine has been used,wherein the engine oil degradation detector includes an engine oil temperature estimation means that estimates a temperature of the engine oil, the use level of the engine oil being corrected with an engine oil degradation coefficient obtained according to the temperature of the engine oil estimated by the engine oil temperature estimation means; wherein the engine oil degradation detector integrates the corrected use levels of the engine oil, and determines that a time to change the engine oil has come when the integrated use level reaches a predetermined value indicating a usable life of the engine oil; and wherein the engine oil estimation means works out an estimated engine oil temperature based upon a cooling water temperature of cooling water that cools the internal combustion engine, and an open/closed state of a control valve provided in a cooling water channel.