Embodiments herein relate to oil condition sensing systems and related methods. In a first aspect, an oil condition sensing system is included having a control circuit, a temperature sensor, and a fluid property sensor, wherein the fluid property sensor measures fluid properties including at least dielectric constant and the oil condition sensing system is configured to automatically detect when an oil change event has occurred, record the fluid property sensor data as new baseline fluid property data after an oil change event has occurred, and evaluate the condition of an engine oil based on a comparison with the baseline fluid property data. The oil condition sensing system can be configured to automatically detect the oil change event by evaluating signals from the fluid property sensor and interpret a change in dielectric constant and/or viscosity crossing a threshold value as an oil change event. Other embodiments are also included herein.

Methods and systems are provided for diagnosis of oil dilution in an engine. In one example, a method may include sealing a crankcase and spinning an engine unfueled to heat and vaporize the oil in response to detection of rich engine operation. Pressure measurements at the sealed crankcase may be collected and compared to a baseline to diagnose a presence of fuel in the oil.

Systems and methods for lubricant dilution detection are disclosed. A method for detecting lubricant dilution for a lubrication system includes detecting a low idle condition. The method includes receiving sensed values indicative of lubricant pressure and lubricant temperature during the low idle condition. The method also includes determining a lubricant pressure threshold based on the sensed value indicative of lubricant temperature. The method further includes determining lubricant dilution based on the sensed value indicative of lubricant pressure and the determined lubricant pressure threshold during the low idle condition. In accordance with a determination that there is lubricant dilution, the method includes outputting an indication of the lubricant dilution.

A method for determining a fuel fraction in the oil of an oil circuit (6), in particular in oil of an oil circuit (6) of an internal combustion engine (7), wherein a variably adjustable oil delivery pump (1) is provided in the oil circuit, which oil delivery pump can be actuated by means of a control unit (4), wherein the control unit performs an adjustment of parameters and/or adaptation values of the oil delivery pump as a function of the viscosity of the oil, wherein a determination of the fuel fraction in the oil is performed on the basis of the parameters and/or adaptation values.

A diagnostic system for a lubrication circuit of an internal combustion engine of a vehicle. The system includes a viscometer for detecting the viscosity of a lubricating liquid of the lubrication circuit, a temperature sensor for detecting the temperature of the lubricating liquid, and a control unit to acquire the state of the lubricating liquid, given by the viscosity detected for a given lubricating liquid condition, which includes the lubricating liquid temperature and the date of last replacement of the lubricating liquid, and for a given condition of use of the engine, and to assess the state of the lubricating liquid by comparing the detected viscosity of the lubricating liquid with the viscosity reference values stored in the database in the same or similar condition of lubricating liquid temperature, date of last replacement of the lubricating liquid and use of the engine.

The disclosure provides a method and a device for determining the engine oil quality of an internal combustion engine. The engine oil quality is determined by evaluation of the switching times of an oil pressure switch of the internal combustion engine after a starting operation of the internal combustion engine.

A computer implemented method system and apparatus for determining remaining life of engine oil in an engine includes generating reference engine profile data by determining reference engine parameters of a reference engine; determining reference engine oil lubrication data based on mechanical testing of an oil sample from the reference engine; generating a reference model by associating the reference engine profile data with the reference engine oil lubrication data; receiving the reference model at an engine apparatus; measuring engine parameters relating to operation conditions of an engine of the engine apparatus; and determining remaining life of engine oil in the engine of the engine apparatus using the reference model and the engine parameters.

A controller for a vehicle is configured to execute a lubricating oil degradation degree acquisition process that calculates a degradation degree of a lubricating oil that lubricates an internal combustion engine, a battery degradation degree acquisition process that calculates a degradation degree of a battery, and an oil change time calculation process that calculates an oil change time for the lubricating oil from the degradation degree of the lubricating oil and the degradation degree of the battery. The oil change time calculation process includes calculating the oil change time so as to become earlier as the degradation degree of the battery increases.

A fluid degradation monitoring system may detect a replacement of a fluid of a machine. The fluid degradation monitoring system may determine, after detecting the replacement of the fluid, a first degradation estimate of the fluid using a first technique based on characteristics relating to an operation of the machine. The fluid degradation monitoring system may detect a transition in a value of a dielectric constant of the fluid from a first phase to a second phase. The fluid degradation monitoring system may determine, after detecting the transition in the value of the dielectric constant, a second degradation estimate of the fluid using a second technique based on characteristics relating to the fluid.

A vehicle liquid testing system includes a liquid testing apparatus with a form factor of a dipstick. The system includes a sensor that detects a property of a fluid in a vehicle and emits a signal indicative of the property. A transmitter receives the signal from the sensor and transmits the signal. A controller receives the signal from the transmitter and compares the signal from the sensor to a threshold level to determine a condition of the fluid.