A positive crankcase ventilation valve for an engine is provided with a valve body defining apertures fluidly coupling a crankcase and an intake manifold of the engine, with each aperture sized to prevent an entrained oil droplet from flowing therethrough. The valve has a valve element supported by the body to selectively cover at least one of the apertures in response to a pressure difference between the manifold and the crankcase to provide variable air flow from the crankcase to the intake manifold. A method includes, in response to an increasing absolute pressure difference between the manifold and the crankcase, passively moving a valve element to selectively cover apertures fluidly coupling the crankcase and the manifold to control an air flow from the crankcase to the intake manifold to a predetermined variable flow profile, and separating oil droplets from the air flow via the apertures.

A method of monitoring the usage of an internal combustion engine is provided. The method comprises performing an engine monitoring routine using a local monitoring device directly attached to an internal combustion engine. The engine monitoring routine includes generating a plurality of data points representative of the crankcase pressure of the internal combustion engine using a pressure sensor of the local monitoring device, processing the generated data points to determine a first value representative of a firing frequency of the internal combustion engine, generating an aggregated summary of the internal combustion engine usage based on the first value, and transmitting identification data for the local monitoring device and the aggregated summary from the local monitoring device to a remote application. The remote application processes the transmitted aggregated summary based on the transmitted identification data to determine engine speed usage data for the internal combustion engine.

A method and a system for diagnosing positive crankcase ventilation (PCV) systems are disclosed. In one example, the method diagnoses a PCV system based on a pressure that may be observed during engine cranking. In another example, the PCV system is diagnosed during vehicle driving conditions after the engine exits cranking.

A breach detection system for an internal combustion engine having a crankcase, an intake manifold, a positive crankcase ventilation valve, a crankcase ventilation tube with a flow control system therein, and a pressure sensor between the flow control system and the crankcase. The flow control system subdivides the crankcase ventilation tube into a plurality of parallel conduits—a first conduit having a normally closed check valve that opens under a first preselected pressure drop in a first direction from the air intake to the crankcase, and a second conduit having either a second check valve that opens under a second preselected pressure drop in a second direction opposite the first direction or a restriction profile having a third preselected pressure drop that is the same in both the first and second direction. When the pressure sensor detects no pressure drop there is a breach in the system.

A pollution control system for a diesel engine includes a PCV valve and an associated vacuum pump having an inlet and an outlet adapted to vent blow-by gas out from a crankcase to an intake manifold on the diesel engine. The vacuum pump associated with the PCV valve selectively modulates vacuum pressure to adjustably increase or decrease a fluid flow rate of blow-by gas venting from the crankcase through the PCV valve.

Systems, devices and methods for diagnosing malfunctioning in a crankcase ventilation (CCV) system are provided. A controller includes a processor and a memory storing instructions that cause the processor to: receive a plurality of pressure values including (i) a first pressure value indicative of a pressure of fluid flowing from a crankcase to a breather assembly of a system, (ii) a second pressure value indicative of a pressure of fluid flowing through a first tube coupled to the breather assembly, and (iii) a third pressure value indicative of a pressure of fluid flowing through a second tube coupled to the breather assembly; determine a pair of pressure differences based on the first pressure value, the second pressure value, and the third pressure value; and detect a malfunctioning in the CCV system based on the pair of pressure differences.

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 leakage detection device detects leakage in a PCV passage that at least includes a scavenging line that communicates between a crank chamber of an engine and a portion of an intake passage of the engine that is on a downstream side of a throttle valve and a fresh air line that communicates between the crank chamber and a portion of the intake passage that is on an upstream side of the throttle valve. The leakage detection device includes a pressure measurement, a first valve and a leakage determination unit. The pressure measurement unit measures pressure in the PCV passage. The first valve opens/closes the fresh air line. The leakage determination unit determines presence or absence of leakage in the PCV passage on a basis of the pressure in the PCV passage at a time when the first valve is closed.

A fault diagnostic system of a vehicle includes a noise module that determines a noise value based on a plurality of differences between samples of a pressure signal generated by a pressure sensor located in a positive crankcase ventilation (PCV) system of an engine. A signal module determines a signal value based on the samples of the pressure signal generated by the pressure sensor located in the PCV system of the engine. A diagnostic value module determines a diagnostic value based on one of: (i) a product of the noise value and the signal value; and (ii) a sum based on the noise value and the signal value. A fault module selectively diagnoses a fault in the PCV system based on the diagnostic value and generates a malfunction indicator within a passenger cabin of the vehicle in response to the diagnosis of the fault in the PCV system.