A method of operating a relief valve assembly for an oil pump includes unblocking a first bypass inlet passage and blocking a first bypass outlet passage, a second bypass inlet passage, and a second bypass outlet passage with a plunger, introducing oil to the relief valve assembly, moving the plunger in a downward direction by a first displacement to unblock the first bypass outlet passage, starting a first bypass of the oil, moving the plunger in the downward direction by a second displacement to block the first bypass inlet passage and unblock the second bypass inlet passage, terminating the first bypass of the oil, moving the plunger in the downward direction by a third displacement to unblock the second bypass outlet passage, and starting a second bypass of the oil.

Methods and systems are provided for diagnosing the functioning of a variable displacement oil pump. In one example, a method may include commanding a change in displacement of the variable displacement oil pump during a vehicle keyed-off condition and diagnosing a degradation of the oil pump based on a corresponding change in an estimated crankcase pressure.

Methods and systems are provided for diagnosing the functioning of a variable displacement oil pump. In one example, a method may include commanding a change in displacement of the variable displacement oil pump during a vehicle keyed-off condition and diagnosing a degradation of the oil pump based on a corresponding change in an estimated crankcase pressure.

A method and system for engine monitoring comprises a plurality of monitoring devices. A master monitoring device is provided which acts as a communication hub for one or more subsidiary monitoring devices. The master monitoring device is incorporated in or directly attached to the internal combustion engine and functions to sense a characteristic of the internal combustion engine. The monitoring device is configured to transmit data representative of the sensed characteristic to a remote application running on a remote device.

A control device for an onboard engine is configured to control the oil discharge pressure of an oil pump and execute, when determining that there may be an abnormality in the control of the oil discharge pressure, a change process that increases the target discharge pressure to a value that is greater than that before it is determined that there may be an abnormality in the control. When a discharge pressure sensor value in a situation in which the discharge pressure is being controlled based on the target discharge pressure increased through execution of the change process does not become greater than or equal to a discharge pressure threshold, the control device sets an upper limit for the engine rotation speed and increases the upper limit as the discharge pressure sensor value increases.

A control device for an onboard engine is configured to control the oil discharge pressure of an oil pump and execute, when determining that there may be an abnormality in the control of the oil discharge pressure, a change process that increases the target discharge pressure to a value that is greater than that before it is determined that there may be an abnormality in the control. When a discharge pressure sensor value in a situation in which the discharge pressure is being controlled based on the target discharge pressure increased through execution of the change process does not become greater than or equal to a discharge pressure threshold, the control device sets an upper limit for the engine rotation speed and increases the upper limit as the discharge pressure sensor value increases.

A lubrication system for an aircraft engine includes an engine lubricant tank including at least a supply port hydraulically connectable to the aircraft engine, a lubricant makeup port, and an overfill port, an auxiliary lubricant tank, a lubricant makeup conduit hydraulically connecting the auxiliary lubricant tank to the lubricant makeup port. The lubricant makeup conduit includes a pump operable to move lubricant from the auxiliary lubricant tank to the lubricant makeup port, and an overfill conduit hydraulically connecting the overfill port to the auxiliary lubricant tank. A method of operating a lubrication system of an aircraft engine of an aircraft is also disclosed.

A lubrication system for an aircraft engine includes an engine lubricant tank including at least a supply port hydraulically connectable to the aircraft engine, a lubricant makeup port, and an overfill port, an auxiliary lubricant tank, a lubricant makeup conduit hydraulically connecting the auxiliary lubricant tank to the lubricant makeup port. The lubricant makeup conduit includes a pump operable to move lubricant from the auxiliary lubricant tank to the lubricant makeup port, and an overfill conduit hydraulically connecting the overfill port to the auxiliary lubricant tank. A method of operating a lubrication system of an aircraft engine of an aircraft is also disclosed.

Disclosed is lubrication for a slow-running two-stroke engine, especially marine diesel engines. The lubrication uses Swirl Injection Principle by locating the lubricant injectors closer to the TDC than of the full stroke of the piston, which is closer than in typical marine diesel engines. This can be achieved by reconstructing cylinder liners or by adding new mounting holes to the cylinder. In case that such reconstruction is not possible, an improvement of SIP principles can also be achieved by directing the spray towards the TDC or to a location on the cylinder liner closer to the TDC as compared to the location of the SIP valves, for example under an angle of more than 30 degrees or even more than 60 degrees when measured from a plane normal to the cylinder axis.

Methods and systems are provided for diagnosing variable oil pump degradation. In one example, a method may include cranking an engine with a motor and monitoring the motor current draw from a battery during cranking. The method may indicate degradation of a variable oil pump coupled to the engine by comparing the motor current draw with a baseline current level.