Methods and systems are provided for filtering an oil dilution amount based on a current value of the oil dilution amount. In one example, filtering the oil dilution amount may include decreasing a sensitivity of filtering at lower oil dilution below a threshold; otherwise, increasing the sensitivity of filtering. The sensitivity of the filtering may be decreased by implementing a larger time constant, while the sensitivity of the filtering may be increased by implementing a smaller time constant.

A method for determining a degree of loading on a filter medium of a filter device on a vehicle through which a fluid flows includes determining an operating characteristic of the filter device based on at least one operating quantity of the vehicle and comparing a predefined reference characteristic of the filter device with the operating characteristic. The degree of loading is derived from a result of the comparing step.

A method of regulating oil pressure within an engine assembly is provided. The engine assembly includes an oil pump configured to provide oil to an oil system of the engine assembly; a piston cooling jet configured to direct a jet of oil from the oil system towards a piston of an engine; and an electronic control valve configured to control the flow of oil to the piston cooling jet. The method includes operating the electronic control valve to provide a flow rate of oil above a threshold flow rate to the piston cooling jet when the engine assembly is operating above a threshold power output or engine running speed; and regulating the pressure of oil within the oil system when the engine assembly is operating below the threshold power output or engine running speed, by operating the electronic control valve.

An engine oil feeding device is provided, which includes a variable-displacement oil pump having an operating chamber and a control oil-pressure chamber, and for changing a capacity of the operating chamber according to a pressure of the control oil-pressure chamber to change its discharging amount, an oil supply channel communicating with the operating chamber and coupled to an oil fed part, and an oil filter. The oil supply channel includes a pump downstream oil channel connecting the operating chamber with the filter and a control oil channel branched from the pump downstream oil channel and coupled to the control oil-pressure chamber. The device also includes a control valve provided in the control oil channel. A starting control is performed in which the valve opening is set larger than a predetermined rate before the pump starts driving and set smaller than the predetermined rate after the pump starts driving.

Methods and systems are provided for filtering an oil dilution amount based on a current value of the oil dilution amount. In one example, filtering the oil dilution amount may include decreasing a sensitivity of filtering at lower oil dilution below a threshold; otherwise, increasing the sensitivity of filtering. The sensitivity of the filtering may be decreased by implementing a larger time constant, while the sensitivity of the filtering may be increased by implementing a smaller time constant.

A device configured to detect a drop of oil pressure includes: a first gate configured to receive an acceleration measured by an acceleration sensor and to output a logical value indicating whether the acceleration falls within a range that is determined by a turning cam tracking diagnosis entry acceleration and a turning cam tracking diagnosis escape acceleration; a second gate configured to invert an output of the first gate; and a third gate configured select and output one of an output value of the second gate or a first value based on a first selection signal. The device is configured to perform a turning cam tracking diagnosis entry when the output value of the third gate is the first value, and the device is configured to not perform the turning cam tracking diagnosis entry when the output value of the third gate is a second value.