A snowmobile including a frame; at least one ski; an engine with an engine air inlet and an exhaust outlet; a turbocharger including an exhaust turbine, and a compressor. An air intake system includes a first flow path connecting the compressor to the atmosphere; a second flow path connecting the compressor to the engine air inlet; an intake bypass flow path connecting atmosphere to the engine air inlet for bypassing the compressor; and an intake bypass valve for controlling the flow through the intake bypass flow path. An exhaust system includes a third flow path connecting the exhaust outlet to the exhaust turbine; a fourth flow path connecting the exhaust turbine to the atmosphere; an exhaust bypass flow path connecting the exhaust outlet to the atmosphere for at least partially bypassing the exhaust turbine; and an exhaust bypass valve for controlling the flow through the exhaust bypass flow path.

A heat exchanger includes a body that includes an at least two opposing surfaces and the at least two opposing surfaces are a trapezoidal. The body of the heat exchanger also includes, an area of cross sectional flow channels through the body. The area of cross-sectional flow channels in a direction perpendicular to the bases of the trapezoid increase or decrease between the two bases.

A method for diagnosing a waste gate valve malfunction in a power generation system is presented. The method includes determining an actual pressure differential across a throttle valve. The method further includes determining an estimated pressure differential across the throttle valve based on one or more first operating parameters of the power generation system. Furthermore, the method includes determining an absolute difference between the actual pressure differential and the estimated pressure differential. Moreover, the method also includes comparing the absolute difference with a threshold value and if the absolute difference is greater than the threshold value, determining an operating condition of the throttle valve. Additionally, the method includes determining whether the waste gate valve has malfunctioned based on the determined operating condition of the throttle valve. An engine controller and a power generation system employing the method are also presented.

A snowmobile has a frame including a tunnel having a passage therethrough, at least one ski, an engine having an engine air inlet and an engine exhaust outlet, and a drive track operatively connected thereto and disposed at least partly below the tunnel around a rear suspension. A heat exchanger connected to the tunnel has heat exchanger engine air inlet and outlet, a cooling air inlet and a cooling air outlet fluidly connected between the cooling air inlet and the passage. A snowmobile has a pipe fluidly connected to the exhaust outlet and having first and second pipe outlets. The snowmobile further has a muffler having first and second muffler inlets and a muffler outlet, a turbocharger, first and second exhaust flow passages, and a valve disposed between the pipe and the first muffler inlet for selectively controlling the flow of exhaust gas flowing through the first exhaust flow path.

Methods and systems are provided for a coolant circuit. In one example, the coolant circuit comprises high and low-temperature radiators, where only one pump is configured to conduct coolant through the entire coolant circuit.

An engine system with exhaust gas recirculation includes a combustion engine, a flow mixer, and a turbocharger. An exhaust flow path and a charge air flow path each extend to an inlet of the flow mixer, and a mixed gas flow path extends between the outlet of the flow mixer and an intake manifold of the engine. A charge air heat exchanger is arranged along the charge air flow path to cool the charge air, and a mixed gas heat exchanger is arranged along the mixed gas flow path to cool mixed charge air and recirculated exhaust gas. The exhaust gas recirculation flow path does not extend through any heat exchangers.

A frame device for a fan module for a main cooler and for a charge air cooler of a motor vehicle, comprising a main frame for the main cooler and a charge air cooler, separate from the latter, for the charge air cooler, wherein a seal is provided between the main frame and the charge air frame. Furthermore, the invention relates to a fan module with such a frame device.

A method for diagnosing a waste gate valve malfunction in a power generation system is presented. The method includes determining an actual pressure differential across a throttle valve. The method further includes determining an estimated pressure differential across the throttle valve based on one or more first operating parameters of the power generation system. Furthermore, the method includes determining an absolute difference between the actual pressure differential and the estimated pressure differential. Moreover, the method also includes comparing the absolute difference with a threshold value and if the absolute difference is greater than the threshold value, determining an operating condition of the throttle valve. Additionally, the method includes determining whether the waste gate valve has malfunctioned based on the determined operating condition of the throttle valve. An engine controller and a power generation system employing the method are also presented.

An ECU that is a diagnostic device includes a calculation unit that is a water temperature obtaining unit obtaining the temperature of a discharge coolant which is a coolant discharged from an engine, a diagnostic unit that diagnoses a thermostat which is a temperature adjusting valve by comparing the temperature of the discharge coolant and a threshold, and a suspending unit that suspends a diagnosis performed by the diagnostic unit. The suspending unit suspends a diagnosis performed by the diagnostic unit in a case where the temperature of the discharge coolant is estimated to be lower than the threshold according to an operating condition of the vehicle even though the thermostat is normal.

A method of controlling a hybrid intercooler system integrated with an air conditioning system includes: starting operation of the air conditioning system by opening first and second air conditioning valves and operating a compressor, when an operation signal of the air conditioning system is determined to be applied; measuring a first temperature by measuring a temperature of compressed air at an outlet of the hybrid intercooler system, after the starting operation of the air conditioning system; and starting operation of a first water cooling unit by opening first and second bypass valves, when the measured first temperature exceeds a predetermined first reference temperature. This method stabilizes the temperature of intake air passing through the inlet of an intercooler using a water cooling unit and increases the cooling efficiency of the intercooler using an air cooling unit.