Methods and systems are provided for pinpointing a source of degradation in a vehicle engine system. In one example, a method includes spinning an engine of a vehicle unfueled in a forward and a reverse direction, in no particular order, and recording a first intake air flow and a second intake air flow, respectively, in an intake of the engine, and where the source of degradation is indicated as a function of both the first air flow and the second air flow. In this way, the degradation of the vehicle engine system may be pinpointed as to being located in the intake manifold, the exhaust system, or the engine.

A method of operating a forced induction gaseous-fueled engine includes mixing gaseous-fuel and engine intake air to form a mixture at a fuel mixer. The method includes delivering the mixture to an intake manifold by at least partially bypassing a charge air cooler.

A cooling system for a gas turbine engine may comprise a plenum extending circumferentially around an outer engine case structure. The plenum may comprise a supply conduit and a return conduit. The supply conduit and the return conduit may be in fluid communication with a heat exchanger. The heat exchanger may be disposed between the outer engine case structure and an inner engine case structure. The plenum may be configured to provide enhance heat transfer for the cooling system.

A method of assisting ignition of a dedicated exhaust gas recirculation (D-EGR) cylinder in a spark-ignited internal combustion engine. The spark igniter has an internal air passage that receives pressurized air and carries the pressurized air down to an exit port in the vicinity of the spark gap of the igniter.

It is aimed to provide an internal combustion engine (10) comprising: an exhaust line (13) configured to receive exhaust gas from the internal combustion engine (10). An intake line (12) is configured to supply pressurized air from an air intake to the internal combustion engine. A heater (20) is disposed adjacent the exhaust line (13) to generate heat that is transported via the exhaust line to an exhaust aftertreatment system (30). A bypass line (11) controllably connects the intake line to the exhaust line to bypass the engine An electric flow generator (40) is arranged in the intake line and/or bypass line between the air intake and the inlet opening to supply intake air to the exhaust line; and a control system is arranged to selectively control the bypass line (11) to provide pressurized intake air from the electric flow generator, via the inlet opening (17) to supply intake air to the exhaust line for transporting heat generated by the heater towards the aftertreatment system.

Interference between an intake manifold and a fuel pipe during a vehicle front collision is prevented in an engine which is longitudinally mounted in an engine room. A vehicle component is arranged on the front side of an intake manifold, and a fuel pipe is arranged on the rear side of the intake manifold. The intake manifold includes a mounting portion on the intake-air downstream end side of a plurality of independent intake pipe portions and connects each of the plurality of independent intake pipe portions to a portion of the engine on one side of the engine in the vehicle width direction. The mounting portion has a front-side mounting portion relatively positioned on the front side and a rear-side mounting portion relatively positioned on the rear side, and the rear-side mounting portion has a higher rigidity than the front-side mounting portion.

Removal and breakage of fuel piping during a vehicle front collision is prevented for an engine mounted longitudinally in an engine compartment. Embodiments include a side structure of the engine having an alternator in front of an intake manifold and fuel piping behind the intake manifold so as to extend in the vertical direction. The intake manifold includes a plurality of independent intake pipe portions each having one end portion connected to one side of the engine in a vehicle width direction, and a surge tank portion to which the other end portions of the independent intake pipe portions are connected. As seen from the rear side, a portion of the fuel piping closer to the surge tank portion is located closer to the one side of the engine in the vehicle width direction than the surge tank portion.

Interference between an intake manifold and a fuel pipe during a vehicle front collision is prevented in an engine which is longitudinally mounted in an engine room. A vehicle component is arranged on the front side of the intake manifold, and the fuel pipe is arranged on the rear side of the intake manifold. The intake manifold includes a plurality of independent intake pipe portions arranged side by side in the vehicle front-rear direction which branch for each of the cylinders of the engine; and a plurality of coupling portions that each couple adjacent independent intake pipe portions to each other in an integral manner A first coupling portion of the plurality of coupling portions positioned on the frontmost side has a lower rigidity than a third coupling portion of the plurality of coupling portions positioned the rearmost side.

An engine system includes an engine with an intake manifold and an exhaust manifold, a turbocharger including a turbine in communication with the exhaust manifold and a compressor in communication with the intake manifold, and a regulator configured to control a flow of exhaust gas through the turbine. A controller of the engine system is operably connected with the regulator and is configured to monitor an engine load and an exhaust gas temperature during operation of the engine, identify a proscribed engine NOx emissions level based on the engine load and the exhaust gas temperature and, when the proscribed engine NOx emissions level is identified, modify the flow of exhaust gas through the turbine to reduce the energy extracted from the exhaust gas by the turbine and reduce a drive power provided to the compressor, thereby reducing a flow of intake air provided to the intake manifold by the compressor.

An evaporated gas leak diagnosis method using an active purge pump is provided to detect a leak of the evaporated gas from a canister in a fuel system. The method includes diagnosing a failure of an active purge pump based on a signal generated by a pressure sensor installed on a vent line that extends from the canister to the atmosphere. The active purge pump is mounted on a purge line for connecting the canister with an intake pipe.