An internal combustion engine includes an internal combustion engine interior and a lubricant disposed in the internal combustion engine interior. The lubricant lubricates a component disposed in the internal combustion engine interior and the lubricant is a water-containing lubricant. In an embodiment, the internal combustion engine interior is fluidically connected to an environment surrounding the internal combustion engine by a ventilation device where the ventilation device has a semipermeable membrane which is impermeable to water and water vapor.

Methods and systems are provided for coordinating throttle bypass flows from brake booster vacuum reservoir, a fuel vapor purge system, and a crankcase ventilation system via active, electrical control of a crankcase ventilation valve. In one example, a method may include actively opening the crankcase ventilation valve to allow crankcase ventilation flow into the engine during conditions in which doing so will not result in engine air flow rate and/or engine fuel flow rate exceeding desired rates. Priority is given first to brake booster replenishment, then to fuel vapor purging, and then to crankcase ventilation during conditions where all three throttle bypass flows are desired.

Methods and systems are provided for coordinating throttle bypass flows from brake booster vacuum reservoir, a fuel vapor purge system, and a crankcase ventilation system via active, electrical control of a crankcase ventilation valve. In one example, a method may include actively opening the crankcase ventilation valve to allow crankcase ventilation flow into the engine during conditions in which doing so will not result in engine air flow rate and/or engine fuel flow rate exceeding desired rates. Priority is given first to brake booster replenishment, then to fuel vapor purging, and then to crankcase ventilation during conditions where all three throttle bypass flows are desired.

This blow-by gas system is provided with: a blow-by gas flow path through which a blow-by gas discharged from an internal combustion engine passes; and an oil separator disposed midway along the blow-by gas flow path. A downstream end of the blow-by gas flow path connects to at least one of a predetermined portion of an intake passageway and a midway portion of an air introduction passageway. The predetermined portion is a portion at which at least some of the blow-by gas that has flowed into the intake passageway flows into the air introduction passageway together with an intake air in the intake passageway.

This blow-by gas system is provided with: a blow-by gas flow path through which a blow-by gas discharged from an internal combustion engine passes; and an oil separator disposed midway along the blow-by gas flow path. A downstream end of the blow-by gas flow path connects to at least one of a predetermined portion of an intake passageway and a midway portion of an air introduction passageway. The predetermined portion is a portion at which at least some of the blow-by gas that has flowed into the intake passageway flows into the air introduction passageway together with an intake air in the intake passageway.

A marine outboard motor is provided with an internal combustion engine comprising an engine block defining at least one cylinder, an air intake configured to deliver a flow of air to the at least one cylinder, a crankcase in which a crankshaft is mounted for rotation about a crankshaft axis which is substantially vertical when the marine outboard is vertical, and a crankcase ventilation system configured to vent blow-by gases from the crankcase and to supply vented blow-by gases to the air intake. The crankcase ventilation system comprises a lubricant separation chamber for separating lubricant from the blow-by gases. The lubricant separation chamber is defined by the crankcase and extends along the length of the crankcase substantially parallel to the crankshaft axis.

A marine outboard motor is provided with an internal combustion engine comprising an engine block defining at least one cylinder, an air intake configured to deliver a flow of air to the at least one cylinder, a crankcase in which a crankshaft is mounted for rotation about a crankshaft axis which is substantially vertical when the marine outboard is vertical, and a crankcase ventilation system configured to vent blow-by gases from the crankcase and to supply vented blow-by gases to the air intake. The crankcase ventilation system comprises a lubricant separation chamber for separating lubricant from the blow-by gases. The lubricant separation chamber is defined by the crankcase and extends along the length of the crankcase substantially parallel to the crankshaft axis.

A blow-by gas leak diagnostic device includes a first PCV flow path, a second PCV flow path, a fresh air inlet, a pressure measurement unit, a first valve that opens and closes the first PCV flow path, a second valve that opens and closes the second PCV flow path, a third valve that opens and closes the fresh air inlet, a valve control unit, and a leak diagnosis unit. The valve control unit controls an opening degree of the third valve when a downstream side of an intake manifold with respect to a throttle valve has a negative pressure, and the second valve is in a closed state. The leak diagnosis unit diagnoses presence or absence of a leak in the first PCV flow path on the basis of an inner pressure of the first PCV flow path measured by the pressure measurement unit.

A blow-by gas leak diagnostic device includes a first PCV flow path, a second PCV flow path, a fresh air inlet, a pressure measurement unit, a first valve that opens and closes the first PCV flow path, a second valve that opens and closes the second PCV flow path, a third valve that opens and closes the fresh air inlet, a valve control unit, and a leak diagnosis unit. The valve control unit controls an opening degree of the third valve when a downstream side of an intake manifold with respect to a throttle valve has a negative pressure, and the second valve is in a closed state. The leak diagnosis unit diagnoses presence or absence of a leak in the first PCV flow path on the basis of an inner pressure of the first PCV flow path measured by the pressure measurement unit.

An electromagnetic valve includes a solenoid having a plunger; a flow path member including a fluid passage flow path having a first flow path, a second flow path, and a relay flow path which is disposed between the first flow path and the second flow path and which connects the first flow path and the second flow path, and a cylindrical space; a valve body movably disposed in the cylindrical space; and a spring which is disposed concentrically with the valve body on an outer peripheral side of the valve body in the cylindrical space and urges the valve body.