An internal combustion engine system includes: an in-cylinder pressure sensor; a crank angle sensor; and a seal portion that seals a space between an outer face of a housing and a wall surface of a cylinder head. A slope that is a ratio of the amount of decrease in a heat release amount relative to the amount of increase in a crank angle is calculated in a period during an expansion stroke from a combustion end point until an opening timing of an exhaust valve. The existence or nonexistence of an abnormality in the sealing function of the seal portion is determined based on whether or not a ratio of the amount of decrease in the slope to the amount of increase in an engine speed is greater than a threshold value.

The present invention relates to a control device (26) for a turbocharger (17) for supplying compressed intake air to an internal combustion engine (1). The control device includes: a storage part (27) configured to pre-store a map (33); a detection part (28) configured to a characteristic parameter; a calculation part (29) configured to obtain an efficiency of the turbocharger on the basis of the detected characteristic parameter; a determination part (30) configured to determine presence of deterioration of the turbocharger by comparing the detected characteristic parameter and the obtained efficiency with the map (33); and an informing part (31) configured to inform a user of a maintenance request.

An apparatus includes an engine module, an in-cylinder content module, and an engine out NOx module. The engine module is structured to interpret engine in-cylinder data regarding an operating condition within a cylinder of an engine, wherein the engine in-cylinder data includes an engine torque, an engine speed, a rail pressure, and a start-of-injection. The in-cylinder content module is structured to interpret at least one additional in-cylinder data point regarding the operating condition within the cylinder of the engine. The engine out NOx module is structured to determine an engine out NOx amount responsive to the engine in-cylinder data and the at least one additional in-cylinder data point.

A machine may comprise a piston; a memory; and an electronic control module. The electronic control module may be configured to obtain information identifying a previous amount of wear of the piston ring and information identifying an initial dimension of a coating of the piston ring; determine a piston ring wear rate based on a cylinder pressure associated with the piston; determine an amount of time between a current time and a time when the previous wear of the piston ring was calculated; calculate a current amount of wear of the piston ring based on the previous amount of wear of the piston ring, the amount of time, and the piston ring wear rate; calculate an amount of damage to the piston ring based on the current amount of wear and the initial dimension; and take a remedial action when the amount of damage exceeds a threshold.

Rationality diagnostic techniques for an intake oxygen sensor are utilized to detect sensor malfunction. A non-intrusive diagnostic technique includes passively detecting when an exhaust gas recirculation (EGR) valve position crosses low/high position thresholds, whereas an intrusive diagnostic technique includes actively commanding the EGR valve to predetermined low/high positions. During a period after the EGR valve position reaches/crosses at least one of the low/high positions/position thresholds, respectively, maximum and minimum intake oxygen concentration is monitored. When the EGR valve position has crossed both the low/high positions/position thresholds and a difference between the maximum and minimum oxygen concentrations is less than a respective difference threshold, a malfunction of the intake oxygen sensor is detected. A malfunction indicator lamp (MIL) could be set to indicate the malfunction. The intrusive technique is additionally or alternatively implemented, such as part of a verification or backup to the non-intrusive technique.

Methods and systems are provided for determining a type of spark plug fouling. In one example, a method may include differentiating spark plug fouling due to soot accumulation from spark plug fouling due to fuel additive accumulation based on a current on a control wire of the spark plug following application of a dwell command. Further, exhaust oxygen sensor degradation and/or exhaust catalyst degradation may be determined based on switching frequencies of one or more exhaust oxygen sensors and the type of spark plug fouling.

A torque request module determines a torque request for an engine based on a driver input. A cylinder control module determines a target fraction of a total number of cylinders of the engine to be activated based on the torque request. An air fuel imbalance (AFIM) module selectively commands that the cylinder control module set the target fraction based on a predetermined fraction of the total number of cylinders of the engine to be activated. The cylinder control module further: sets the target fraction based on the predetermined fraction in response to the command; and activates and deactivates opening of intake and exhaust valves of the cylinders of the engine based on the target fraction. The AFIM module further, while the target firing fraction is set based on the predetermined fraction, selectively diagnoses the presence of an AFIM fault based on samples of a signal from an oxygen sensor.

Methods and systems for exercising a genset are disclosed herein. The method includes detecting whether the genset is in a first mode or a second mode, and activating a plurality of exercise cycles of the genset. Activating the plurality of exercise cycles comprises, in response to detecting the genset is in the first mode, ignite fuel to activate the genset during each of the plurality of exercise cycles of the genset; and in response to detecting the genset is in the second mode, cranking the genset without igniting fuel during at least a first subset of the plurality of exercise cycles.

A work vehicle including an internal combustion engine that generates power and an exhaust gas treatment device that treats exhaust gas emitted from the internal combustion engine, the work vehicle includes: a detection unit that detects an abnormality of the exhaust gas treatment device; an output restriction unit that restricts output of an output generation device included in the work vehicle when the detection unit detects the abnormality of the exhaust gas treatment device; a display control unit that causes a display unit to display information that the restriction on the output is allowed to be temporarily released; and a releasing unit that releases the restriction on the output in response to an instruction to temporarily release the restriction on the output.

A first computer-implemented diagnostic method can run in response to an imminent deceleration fuel cutoff (DFCO) event. A second computer-implemented diagnostic method can run on engine shutdown. Both diagnostic methods involve controlling fuel injectors and a fuel pump to make the fuel rail pressure change from a desired minimum to a desired maximum. Measurements from the fuel rail pressure sensor at these endpoints can then be used to detect a fault of the fuel rail pressure sensor. One or both diagnostic methods can be implemented.