An arrangement for removing blow-by gases from a crankcase of an internal combustion engine, the blow-by gases being able to be supplied to an air intake system via a tube device, the tube device being connected or connectable to a component assigned to the air intake system and to a component which is in fluid connection to the crankcase. The tube device including a blow-by conduit. The risk of a leaking or incorrectly mounted tube device is avoided in that the tube device has a diagnostic conduit, a spurious air flow being detectable via the diagnostic conduit when the tube device is not tightly connected or is not connected.

A cylinder head cover includes a main body and a side projection portion. The main body is provided so as to cover a cylinder head, and collects a blowby gas. The side projection portion discharges the blowby gas toward an intake passage. The cylinder head cover includes a cover gas passage through which the blowby gas flows from a main body gas passage to an outlet of the side projection portion. A minimum passage cross-sectional area portion of the cover gas passage is provided not in the side projection portion but in the main body gas passage. The main body has a hole or a projection branch passage at a position of the main body gas passage that is downstream of the minimum passage cross-sectional area portion. The main body, the side projection portion, and the hole or the projection branch passage are integrally molded.

An intake manifold assembly for a vehicle engine includes an intake manifold housing defining a main chamber having perimeter walls and an open upper end; a charge air cooler (CAC) positioned in the main chamber and having an upper cover plate defining a sealing flange; and an integrated positive crankcase ventilation (PCV) system. The PCV system includes a PCV chamber integrally formed into an upper surface of one of the perimeter walls, the PCV chamber having an open upper end; a PCV port integrally formed with the intake manifold housing and in fluid communication with the PCV chamber; a distribution port defined by a wall of the PCV chamber and in fluid communication with an outlet plenum of the intake manifold. Upon securing the CAC to the intake manifold housing, the CAC sealing flange provides a sealed closure for the intake manifold main chamber and the PCV chamber.

Methods and systems are provided for a ducted plenum of a positive crankcase ventilation system for an engine. In one example, the ducted plenum may include a plurality of ducts coupled to a central chamber and an oil separator and valve arranged downstream of the central chamber. The ducted plenum may vent gases from an engine crankcase and deliver the vented gases to the engine intake system.

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.

An internal combustion engine may be used to compress natural gas for vehicle fuel. The engine may contain a plurality of gas compression cylinders, at least one standard combustion cylinder to drive the compression cylinders, and a common crankshaft in a crankcase coupling the compression cylinders and the at least one standard combustion cylinder. Some combustible gas being compressed may leak past the piston rings of the compression cylinders into the engine crankcase posing a safety concern. This invention eliminates this concern by actively flushing the crankcase at a higher rate than normal.

To improve the oil separation performance in an oil separation device for an internal combustion engine. The oil separation device (10) comprises a gas liquid separation passage (56) internally defined by a lower wall, an upper wall and a pair of side walls, and extending in a horizontal direction, a gas inlet (54) and a gas outlet (63) provided on either end of the gas liquid separation passage, a plurality of lower partition walls (56H) projecting upward from the lower wall, and a plurality of upper partition walls (56J) projecting downward from the upper wall. The lower partition walls and the upper partition wall are tilted with respective the length wise direction in plan view so as to define a spiral passage. The lower wall is inclined with respect to a horizontal plane such that an upstream part of the lower wall is lower than a downstream part of the lower wall with respect to a direction of the swirl flow.

An oil mist separator (10) for a crankcase ventilation (11) such as in an internal combustion engine (13) for separating oil particles from a gaseous fluid, in particular blow-by gas is disclosed. The oil mist separator (10) has at least one nozzle plate (24). The at least one nozzle plate (24) is arranged in a flow way of the gaseous fluid. The nozzle plate (24) has at least one aperture (26; 126) for the gaseous fluid. The oil mist separator (10) further has at least one impact surface (32; 132). The at least one impact surface (32; 132) is arranged downstream of the nozzle plate (24) relating to the flow of the gaseous fluid. The at least one impact surface (32; 132) can be moved away from the at least one nozzle plate (24) in an opening direction (36) against a pretension force by influence and dependent on a flow of the gaseous fluid through the at least one aperture (26; 126). At least one aperture is formed as a nozzle aperture (26) and at least one control protrusion (42; 142) for controlling the flow cross-section of at least one aperture (26; 126) is attached to at least one impact surface (32).

An ECU functioning as a diagnostic device includes an information acquisition portion acquiring a flow rate of a fluid flowing through an intake pipe, and a diagnostic portion performing a diagnosis on a second purge pipe employed as a fuel gas pipe regarding a connection failure. The diagnostic portion diagnoses a connection failure of the fuel gas pipe according to magnitude of a pulsation of the flow rate acquired by the information acquisition portion.

A blowby gas return apparatus is provided that achieves inhibition of condensation of water vapor in blowby gas in branched return passages. A blowby gas return apparatus that returns blowby gas generated in an engine having a plurality of cylinders to an intake system of the engine includes a distribution portion inside a head cover of the engine, and distributes the blowby gas to intake paths of the cylinders. The distribution portion includes an introduction portion through which the blowby gas is introduced and a plurality of branch passages communicating with the introduction portion, plurality of branch passages branching from the introduction portion to communicate with the intake paths.