A method and a system for sensing engine oil deterioration are disclosed. The method includes measuring an engine RPM, load (Load), and an engine temperature (Temp), calculating the amount of change in a deterioration factor (f (RPM, Load, Temp) of engine oil per revolution of an engine using the measured engine RPM, load, and the engine oil temperature, and then calculating the engine oil deterioration degree at a current time point by accumulating a value obtained by multiplying the calculated amount in change of the deterioration factor (f (RPM, Load, Temp) by an engine revolutions during a predetermined sampling cycle (Δr) to a previous engine oil deterioration degree.

A method for operating an internal combustion engine that is supplied with lubricating oil via an oil circuit. A measurement value of the total base number and/or a measurement value of the oxidation of lubricating oil currently used in the oil circuit for the lubrication is detected. Dependent on the established measurement value of the total base number and/or dependent on the established measurement value of the oxidation an exchange oil quantity for the oil circuit is determined. Currently used lubricating oil to an extent corresponding to the exchange oil quantity is removed from the oil circuit and new lubricating oil to an extent corresponding to the exchange oil quantity is supplied to the oil circuit.

A method for operating an internal combustion engine wherein the internal combustion engine to be operated is supplied with lubricating oil via an oil circuit. A measurement value of a total base number and/or a measurement value of the viscosity of the lubricating oil currently used in the oil circuit for the lubrication is detected. Dependent on the established measurement value of the total base number and/or dependent on the established measurement value of the viscosity an exchange oil quantity for the oil circuit is determined. Currently used lubricating oil to an extent corresponding to the exchange oil quantity is removed from the oil circuit. New lubricating oil to an extent corresponding to the exchange oil quantity is supplied to the oil circuit.

A lubricant deterioration detection device of the present invention includes a gas sensor that selectively detects a carbonyl compound. The gas sensor is configured to detect the carbonyl compound from at least one of formaldehyde, acetaldehyde, propanal, butanal, pentanal, n-hexanal, n-heptanal, formic acid, and acetic acid. The detection deterioration device further includes an oil removal portion that removes an oil mist generated from the lubricant.

A method for operating an internal combustion engine wherein the internal combustion engine to be operated is supplied with lubricating oil via an oil circuit. A measurement value of a total base number and/or a measurement value of the viscosity of the lubricating oil currently used in the oil circuit for the lubrication is detected. Dependent on the established measurement value of the total base number and/or dependent on the established measurement value of the viscosity an exchange oil quantity for the oil circuit is determined. Currently used lubricating oil to an extent corresponding to the exchange oil quantity is removed from the oil circuit. New lubricating oil to an extent corresponding to the exchange oil quantity is supplied to the oil circuit.

A method for operating an internal combustion engine that is supplied with lubricating oil via an oil circuit. A measurement value of the total base number and/or a measurement value of the oxidation of lubricating oil currently used in the oil circuit for the lubrication is detected. Dependent on the established measurement value of the total base number and/or dependent on the established measurement value of the oxidation an exchange oil quantity for the oil circuit is determined. Currently used lubricating oil to an extent corresponding to the exchange oil quantity is removed from the oil circuit and new lubricating oil to an extent corresponding to the exchange oil quantity is supplied to the oil circuit.

A lubricant deterioration detection device of the present invention includes a gas sensor that selectively detects a carbonyl compound.

A system includes a sensor configured to be in contact with lubricant within an engine of a vehicle system. The sensor includes a sensing region circuit that is configured to generate stimuli at different times during an operational life of the engine. The system also includes one or more processors configured to receive signals from the sensor. The signals are representative of responses of the lubricant to the stimuli. The one or more processors are configured to analyze the responses and determine a characteristic of the lubricant that represents one or more of a total base number (TBN) or a total acid number (TAN) of the lubricant. The one or more processors are configured to determine an unhealthy state of one or more of the engine or the lubricant based on the characteristic of the lubricant that is determined.