The cooling apparatus of the engine according to the invention supplies the cooling water directly to the cylinder block water passage from the cylinder head water passage when the engine temperature is between first and second temperatures, and a supply of the cooling water to the heat exchanger is not requested. The first and second temperatures are lower than the engine completely-warmed temperature. The apparatus supplies the cooling water discharged from the cylinder block and head water passages, to the water passages through the heat exchanger when the engine temperature is between the second temperature and the engine completely-warmed temperature, and the supply of the cooling water to the heat exchanger is not requested.

An outboard motor includes an engine, a cooling water passage, a pump that is driven in conjunction with the engine, an inlet water passage that branches from the cooling water passage, an oil cooler, an outlet water passage, a first thermostat located in the cooling water passage, and a second thermostat. The pump takes outside water into the cooling water passage. The oil cooler includes a water-storing space into which water in the inlet water passage is taken. The outlet water passage is connected to an outlet of the oil cooler. The first thermostat increases and decreases the flow rate of water flowing through the engine. The second thermostat is located at the outlet or at the outlet water passage, and increases and decreases the flow rate of water flowing through the outlet water passage.

An engine cooling system having an EGR cooler is disclosed. The system includes a cylinder head provided on a cylinder block, a coolant pump that pumps a coolant to a coolant inlet side of the cylinder block, an EGR cooler that is branched from a coolant line between the coolant pump and the cylinder block, and is provided in a circulation line through which a coolant is recirculated to an inlet of the coolant pump, and a coolant control valve unit that is provided in a coolant output side of the cylinder head to receive a coolant exhausted from the cylinder head and a coolant exhausted from the cylinder block and controls coolants distributed to coolant parts.

An outboard motor includes an engine, a cooling water passage, a pump that is driven in conjunction with the engine, an inlet water passage that branches from the cooling water passage, an oil cooler, an outlet water passage, a first thermostat located in the cooling water passage, and a second thermostat. The pump takes outside water into the cooling water passage. The oil cooler includes a water-storing space into which water in the inlet water passage is taken. The outlet water passage is connected to an outlet of the oil cooler. The first thermostat increases and decreases the flow rate of water flowing through the engine. The second thermostat is located at the outlet or at the outlet water passage, and increases and decreases the flow rate of water flowing through the outlet water passage.

A vehicle propulsion system includes a prime mover having a coolant inlet and a coolant outlet, a coolant control valve having a valve inlet in communication with the prime mover coolant outlet, a first valve outlet, and a second valve outlet, a bypass flow path in communication with first valve outlet and the prime mover coolant inlet, a heat exchange flow path in communication with the second valve outlet and the prime mover inlet, a heat exchanger in the heat exchange flow path, a first temperature sensor in the bypass flow path for generating a first temperature signal, a second temperature sensor in the heat exchange flow path for generating a second temperature signal, and a controller for providing a coolant control valve command signal to the coolant control valve, using a normalized gain coefficient.

A heat exchange system for a vehicle includes: a first cooling circuit (L1-1, L1-2) is configured to cool an internal combustion engine; a second cooling circuit (L2-1, L2-2) is configured to cool a driving electric motor outputs a driving force; a first heat exchanger (106) is configured to exchange heat between the first cooling circuit and the second cooling circuit; a first sensor (151) is configured to detect a temperature of the first cooling circuit; a second sensor (152) is configured to detect a temperature of the second cooling circuit; and a controller (155) is configured to execute control of performing heat exchange between a coolant in the first cooling circuit and a coolant in the second cooling circuit using the first heat exchanger when the temperature detected by the first sensor is lower than the temperature detected by the second sensor.

Methods and systems are provided for regulating coolant flow in a vehicle cooling system during an engine startup event. In one example, a method may include, during an engine startup event, controlling a flowpath of an engine coolant in a vehicle cooling system via a passive valve and an actively regulatable valve, and responsive to an engine coolant temperature below a threshold at the engine startup event, isolating the flowpath of engine coolant to a subsection of the cooling system to enable rapid warming of the engine coolant without stagnating the engine coolant at an engine. In this way, engine coolant may be rapidly warmed at an engine startup event, via coolant flow isolation, rather than coolant flow stagnation, which may decrease uneven heating of engine system components, and which may thus prolong a functional lifetime of the engine system.

A cooling system selectively cools an engine and an exhaust gas recirculation (EGR) component of the engine. The cooling system includes a plumbing system with a plurality of flow branches, including an engine branch, an EGR branch, and a feed branch. The engine branch defines an engine flow passage through which the coolant flows to cool the engine. The EGR branch defines an EGR flow passage through which the coolant flows to cool the EGR component. The feed branch defines a feed flow passage. The cooling system has a first operating configuration in which the EGR flow passage is configured to receive coolant flow from the engine flow passage. The cooling system has a second operating configuration in which the EGR flow passage is configured to receive coolant flow from the feed flow passage instead of the engine flow passage.

A coolant temperature sensor abnormality determination device includes a determination unit configured to determine whether or not two coolant temperature sensors, which are configured to detect the temperature of the coolant, have an abnormality. The determination unit has a determination permission condition under which a reference temperature is set to an estimated temperature of a present time point and the estimated temperature is then changed from the reference temperature by a determination temperature. The determination unit is configured to determine, when the determination permission condition is satisfied, that the two coolant temperature sensors are functioning normally if a discrepancy between detection values of the two coolant temperature sensors is less than a normal temperature that is less than or equal to the determination temperature.

A cooling system selectively cools an engine and an exhaust gas recirculation (EGR) component of the engine. The cooling system includes a plumbing system with a plurality of flow branches, including an engine branch, an EGR branch, and a feed branch. The engine branch defines an engine flow passage through which the coolant flows to cool the engine. The EGR branch defines an EGR flow passage through which the coolant flows to cool the EGR component. The feed branch defines a feed flow passage. The cooling system has a first operating configuration in which the EGR flow passage is configured to receive coolant flow from the engine flow passage. The cooling system has a second operating configuration in which the EGR flow passage is configured to receive coolant flow from the feed flow passage instead of the engine flow passage.