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 turbocharger is provided and includes a compressor housing and a recirculation slit and a recirculation passage provided at an inlet of the compressor housing to enable air flowing into the compressor to be recirculated. A gas supply part supplies blow-by gas towards the inlet of the compressor housing to allow blow-by gas to be joined with air recirculated through the recirculation slit and the recirculation passage and to guide recirculating air towards a compressor wheel.

The disclosure relates to a method for leakage diagnosis. The method includes influencing the introduction of gas along a crankcase aeration line into a crankcase of an internal combustion engine and acquiring a measurement signal profile by an exhaust-gas sensor arranged in an exhaust-gas tract of an internal combustion engine. The measurement signal profile is characteristic of at least one exhaust-gas property of the exhaust gas. The method includes providing an expected measurement signal profile which is characteristic of the exhaust-gas property of the exhaust gas in the exhaust-gas tract based on the influence on the introduction of gas into the crankcase. Additionally, the method includes comparing the acquired measurement signal profile with the expected measurement signal profile and identifying that the crankcase ventilation line has a leak if, during the comparison, the acquired measurement signal profile deviates from the expected measurement signal profile by a predetermined threshold value.

The blow-by gas treating device 100 has a main structure portion 101 which separates oil OL from the blow-by gas BG and an outlet portion 40 which supplies gas G having been separated from the blow-by gas BG to an intake system. The main structure portion 101 has a first blow-by gas taking-in portion 111, a second blow-by gas taking-in portion 112, a separating portion 330 which separates the blow-by gas BG into oil OL and gas G, a first oil guiding portion 151 which guides the oil OL to a front side, a second oil guiding portion 152 which guides the oil OL to a rear side, a first oil drain 161 which discharges the oil OL into the engine, and a second oil drain 162 which discharges the oil OL into the engine.

Systems are provided for a crankcase ventilation system. In one example, a crankcase ventilation (CCV) system for an engine configured to transmit crankcase gases into a clean side air duct, the clean side air duct comprising a sensor and a crankcase ventilation spigot, wherein the crankcase ventilation spigot is configured to be disposed downstream of the sensor, the crankcase ventilation spigot having an outlet configured to direct crankcase gases emerging from the crankcase ventilation spigot away from the sensor.

An abnormality determination device of an internal combustion engine in which a breather line connects an intake-air path positioned upstream from a forced-induction system and a crankcase includes an intake-air flow rate sensor that detects an intake air flow rate in the intake-air path, a pressure sensor that detects a pressure of the breather line, and an abnormality determination unit that determines abnormality of the breather line. The abnormality determination unit estimates an intake air resistance of the intake-air path from the pressure when the engine is under low load conditions under which the intake air flow rate is less than a predetermined value and the pressure when the engine is under high load conditions under which the intake air flow rate is the predetermined value or greater and determines abnormality of the breather line when the intake air resistance is less than a threshold.

An evaporated fuel treatment apparatus includes an abnormality determination unit that determines an abnormality of a purge passage. The abnormality determination unit changes an operating cycle of a purge control valve to a cycle longer than an initial set value while maintaining a duty ratio of the purge control valve set according to an operating state of an internal combustion engine, and determines an abnormality of the purge passage based on a first variation range and a second variation range calculated from a detection value detected by an airflow meter before and after the change of the operating cycle.

An engine includes: an exhaust manifold 7 close to one of left and right side surfaces of an engine; a turbocharger 60 having an exhaust-side inlet connected to the exhaust manifold 7; and a rocker-arm-chamber-integrated intake manifold 8 being disposed on an upper surface of a cylinder head 5 and integrally including a rocker arm chamber 90 and an intake manifold 6. The intake manifold 8 has a wall 101 dividing the rocker arm chamber 90 close to the one of the left and right side surfaces of the engine 1 and the intake manifold 6 close to the other of the left and right side surfaces to isolate the rocker arm chamber 90 and the intake manifold 6 from each other. The rocker arm chamber 90 has, in its upper portion, a positive crankcase ventilation device 69 protruding therefrom and being configured to return blowby gas to an intake system. The positive crankcase ventilation device 69 has, in its side surface, a blowby-gas discharge port 67 connected with a gas conduit 68 through which blowby gas is delivered to an intake-side inlet of the turbocharger 60.

An engine control device is provided, which includes a blowby gas passage connecting an engine body to an intake passage so that blowby gas leaked from a combustion chamber is recirculated to the intake passage, a boost pressure changer configured to change a boost pressure of a turbocharger, and a controller configured to set a target boost pressure and control the boost pressure changer. The turbocharger includes a turbine which is provided to an exhaust passage and driven by exhaust gas, and a compressor which is provided to the intake passage and rotary driven by the turbine to boost intake air. The blowby gas passage is connected to the intake passage near the compressor. The controller corrects the target boost pressure when an ambient temperature is below a given determination temperature, to be higher than the target boost pressure when the ambient temperature is at or above the determination temperature.

Systems are provided for a crankcase ventilation system. In one example, a crankcase ventilation (CCV) system for an engine configured to transmit crankcase gases into a clean side air duct, the clean side air duct comprising a sensor and a crankcase ventilation spigot, wherein the crankcase ventilation spigot is configured to be disposed downstream of the sensor, the crankcase ventilation spigot having an outlet configured to direct crankcase gases emerging from the crankcase ventilation spigot away from the sensor.