Methods and systems are provided for using a crankcase vent tube pressure or flow sensor for diagnosing a location and nature of crankcase system integrity breach. The same sensor can also be used for diagnosing air filter plugging and PCV valve degradation. Use of an existing sensor to diagnose multiple engine components provides cost reduction and sensor compaction benefits.

A learned neural network learned in weights using an engine load, an engine speed, and an intake pressure inside the engine intake passage downstream of the throttle valve (19) as input parameters of the neural network and using leakage of blow-by gas from a blow-by gas feed path (20) as a truth label is stored. At the time of operation of the vehicle, the learned neural network is used to detect the abnormality of leakage of blow-by gas from the blow-by gas feed path (20) from the above input parameters.

A learned neural network learned in weights using an engine load, an engine speed, and an intake pressure inside the engine intake passage downstream of the throttle valve (19) as input parameters of the neural network and using leakage of blow-by gas from a blow-by gas feed path (20) as a truth label is stored. At the time of operation of the vehicle, the learned neural network is used to detect the abnormality of leakage of blow-by gas from the blow-by gas feed path (20) from the above input parameters.

Methods and systems are provided for indicating crankcase breach due to disconnection of a crankcase vent tube from an engine on a clean air side or broken crankcase vent tube. In one example, a maximum possible change in crankcase vent tube pressure is estimated for each pedal transient of a drive cycle. The change for a plurality of transients in averaged and compared to a threshold to identify vent tube disconnection.

Methods and systems are provided for indicating crankcase breach due to disconnection of a crankcase vent tube from an engine on a clean air side or broken crankcase vent tube. In one example, a maximum possible change in crankcase vent tube pressure is estimated for each pedal transient of a drive cycle. The change for a plurality of transients in averaged and compared to a threshold to identify vent tube disconnection.

A method is provided for detecting a leak in a crankcase breather of an internal combustion engine, in which a cavity of a crankcase is connected in a gas conducting manner to a fresh air section of the internal combustion engine. A pressure sensor is provided for measuring a pressure in the cavity. An electronic control unit is provided for evaluating the signals of the pressure sensor. The method includes: measuring of a gas pressure by way of the pressure sensor in the crankcase breather system at a defined rotational speed and load of the internal combustion engine, comparing an actual pressure value with a setpoint pressure value, detecting a leak if the setpoint pressure value is exceeded. As a result of the method, an air flow meter can be dispensed with and a satisfactory separation effect is produced between a satisfactory system and a defective system.

Methods and systems are provided for adjusting a flow profile of a windage tray. In one example, a method for operation an engine system is provided that includes operating an engine to perform combustion, determining an engine speed, and adjusting a flow profile of a plurality of deflectors in a windage tray positioned in a crankcase based on the engine speed.

Methods and systems are provided for adjusting a flow profile of a windage tray. In one example, a method for operation an engine system is provided that includes operating an engine to perform combustion, determining an engine speed, and adjusting a flow profile of a plurality of deflectors in a windage tray positioned in a crankcase based on the engine speed.

Methods for preventing a premature ignition of a cylinder charge in advance of a planned ignition point in an internal combustion engine are provided. In one method, a pressure in a crankcase of the internal combustion engine is adjusted so as to prevent lubricating oil constituents from being transported from the crankcase to a combustion chamber of a cylinder of the internal combustion engine due to a pressure ratio between the crankcase and the combustion chamber. In another method, an ignition point for a cylinder of the internal combustion engine is adjusted in a given operating range of the internal combustion engine in such a way that the adjusted ignition point brings about a knocking combustion in the cylinder. Internal combustion engines having a device for preventing a premature ignition of a cylinder charge in advance of a planned ignition point are also provided.