An engine oil state control device for controlling a fuel mixture ratio of a fuel mixed in an engine oil of an engine on which a predetermined combustion control is performed includes comprising a fuel mixture ratio acquisition part configured to acquire the fuel mixture ratio, and an oil temperature rise control part configured to perform an oil temperature rise control for increasing an evaporation rate of the fuel mixed in the engine oil if the fuel mixture ratio is equal to or greater than a first threshold.

A method of determining the total evaporation rate of fuel from an oil sump of an engine comprising: a) defining for said fuel, a plurality (n-1) of zones, each zone comprising a separate temperature range, and corresponding to a particular fuel constituent portion; b) determining or estimating the mass of said particular fuel constituent portion present in the sump for each zone; c) for each zone, determining an evaporation rate based on oil temperature; and the corresponding mass determined in step b); d) summing the evaporation rates for each zone from step c) to provide said total evaporation rate.

The invention relates to a monitoring system (SY1) for monitoring an engine (6) comprising: a sensor unit (U1) connected via an inlet line (12) to an oil circuit (C1) of the engine, the sensor unit comprising one or more sensors (SN) for measuring first parameters representative of the quality of an oil (OL) taken from the oil circuit; an analysis unit (U2) for establishing, based on the first parameters (PR1) or second parameters (PR2) obtained from the first parameters, whether at least one predefined condition (CN) is met, by comparing the first or second parameters with at least one threshold value; and a detection unit (U3) configured to detect a deterioration (EVT) of the quality of the oil representative of an abnormal state of the engine, if at least one predefined condition (CN) is met. The invention also relates to a corresponding method.

An internal combustion engine comprises a fuel injection valve which has a needle, wherein a valve opening speed of the needle during post injection is raised as compared with a valve opening speed of the needle during main injection if a pressure of the fuel is not more than a first predetermined pressure, while the valve opening speed of the needle during the post injection is lowered as compared with the valve opening speed of the needle during the main injection if the pressure of the fuel is not less than a second predetermined pressure that is a pressure larger than the first predetermined pressure, when a requested post injection fuel amount is larger than an injection amount threshold value.

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.

A control device of an internal combustion engine including an electronic control unit configured to execute: a base injection amount calculation process of calculating a base value; an injection valve operation process of operating the fuel injection valve; a feedback process of correcting an injection amount in the injection valve operation process; and a determination process of determining whether or not the amount of fuel flowing into the cylinders other than fuel injected from the fuel injection valve is equal to or larger than a threshold value. When it is determined as a result of the determination that the amount of fuel flowing into the cylinders other than the fuel injected from the fuel injection valve is equal to or larger than the threshold value, the electronic control unit (does not execute the process of injecting fuel from the fuel injection valve with the feedback process stopped.

A fuel removal method is for an internal combustion engine that has a closed- and open-loop control system and a lubricant circuit containing a lubricant. The closed- and open-loop control system has characteristic values for operation of the internal combustion engine. The method includes carrying out a load point shift starting from a first operating point of the internal combustion engine to a second operating point of the internal combustion engine with the aid of the closed- and open-loop control system. The load point shift is carried out when a fuel characteristic value, which characterizes a fuel quantity formed in the lubricant, is greater than or equal to a fuel threshold value. The second operating point having a second scavenging gradient which is greater than a first scavenging gradient of the first operating point.

A method is provided for detecting fuel discharge from a lubricant in a housing of an internal combustion engine. A first lambda deviation is measured by a lambda sensor for a first mass air flow supplied in an intake tract of the engine. A second lambda deviation is measured by the lambda sensor for a second mass air flow that differs from the first mass air flow, and is supplied in an intake tract of the engine. An actual comparative value is calculated from the measured first and second lambda deviations. A desired comparative value indicative of the fuel discharge is calculated from a first desired lambda deviation for the first mass air flow, and a second desired lambda deviation is calculated for the second mass air flow. The fuel discharge is detected based on a comparison of the actual comparative value and the desired comparative value.

A control device of an internal combustion engine including an electronic control unit configured to execute: a base injection amount calculation process of calculating a base value; an injection valve operation process of operative the fuel injection valve; a feedback process of correcting an injection amount in the injection valve operation process; and a determination process of determining whether or not the amount of fuel flowing into the cylinders other than fuel injected from the fuel injection valve is equal to or larger than a threshold value. When it is determined as a result of the determination that the amount of fuel flowing into the cylinders other than the fuel injected from the fuel injection valve is equal to or larger than the threshold value, the electronic control unit (does not execute the process of injecting fuel from the fuel injection valve with the feedback process stopped.

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.