A control method for a vehicle, provided with an integrated coolant control valve, includes; performing, by a controller, a fault diagnosis of the integrated coolant control valve; determining, by the controller, whether a position sensor is faulty, the position sensor measuring a position of a cam and outputting a corresponding position output when the controller determines that the integrated coolant control valve is faulty; moving the cam for opening and closing a plurality of valves to a maximum position by operating the integrated coolant control valve when the controller determines that the position sensor is faulty; stopping the operation of the integrated coolant control valve by the controller; and limiting a torque output of an engine by the control of the controller according to the position of the cam.

A cooling system for an internal combustion engine comprises a fluid circuit having an intercooler, a main cooler and a precooler. The intercooler is configured for receiving coolant and configured for heat exchange relation between the coolant and engine compressed air. The main cooler is configured for receiving the coolant from the intercooler and the internal combustion engine and configured for selectively delivering a first portion of the coolant from the main cooler to the precooler. The precooler is configured to deliver a flow of the coolant to the intercooler. The main cooler and the precooler are configured for cooling the coolant by heat exchange with at least one cooling flow.

A control method and a control device are provided for an internal combustion engine structured to vary a mechanical compression ratio by varying a range of slide of a piston with respect to a cylinder bore, and structured to control a flow of cooling water in a water jacket formed around the cylinder bore, wherein variation of the mechanical compression ratio causes the piston to slide on a corroded portion formed in the cylinder bore. A control process includes: acquiring a temperature correlating with a cylinder bore wall temperature; and stopping the flow of cooling water in the water jacket, in response to a condition that the acquired temperature is lower than a preset temperature point.

Methods and systems for managing a monitoring of an engine cooling system. A transient condition associated with an engine system is identified. A determination is made as to whether the transient condition is a delay condition based on whether the transient condition exceeds a transient threshold. A determination is made, in response to a determination that the transient condition is not the delay condition, as to whether a period of time that has passed since a previously identified delay condition meets a time threshold. Monitoring of a health of the engine cooling system is enabled in response to a determination that the period of time meets the time threshold.

An intake-air temperature controlling device for an engine is provided, which includes an engine body, an intake passage, an air intake part, an intake air temperature adjuster configured to adjust air temperature taken in through the air intake part to the passage, and a controller. An operating range in which the CI combustion is performed has a lean operating range in which A/F of mixture gas formed inside the cylinder, or G/F that is a relationship between the total weight G of gas inside the cylinder and a weight F of fuel fed to the cylinder is relatively low, and a rich operating range in which the A/F or G/F is relatively high. When the engine is in the lean operating range, the controller outputs a control signal to the intake air temperature adjuster so that the air temperature is increased, as compared in the rich operating range.

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.

A control method and a control device are provided for an internal combustion engine structured to vary a mechanical compression ratio by varying a range of slide of a piston with respect to a cylinder bore, and structured to control a flow of cooling water in a water jacket formed around the cylinder bore, wherein variation of the mechanical compression ratio causes the piston to slide on a corroded portion formed in the cylinder bore. A control process includes: acquiring a temperature correlating with a cylinder bore wall temperature; and stopping the flow of cooling water in the water jacket, in response to a condition that the acquired temperature is lower than a preset temperature point.

A coolant control system includes: a high temperature radiator communicating with an engine through a high temperature coolant line, a high temperature coolant pump, a coolant temperature sensor, a low temperature radiator, a low temperature coolant pump, a water-cooled intercooler, an intake air temperature sensor, bypass valves provided upstream and downstream of the water-cooled intercooler for selectively controlling the high temperature coolant or the low temperature coolant to flow through the water-cooled intercooler, an ambient temperature sensor, a radiator bypass line connected to the high temperature coolant line and bypassing the high temperature radiator, a thermostat to selectively flow the high temperature coolant to the radiator bypass line, and a controller for controlling the operations of the low temperature coolant pump, the bypass valve and the thermostat in accordance with a vehicle operation state.

An engine device including an engine and a carburetor that vaporizes a liquefied fuel gas from a fuel gas source for storing a liquefied fuel gas, in which a part of coolant in the engine is distributed to the carburetor. The engine device further includes a water-cooled exhaust manifold having a coolant passage for cooling an exhaust gas passage and a path switching mechanism for connecting a coolant inlet of the carburetor to a carburetor coolant outlet of the engine or to a coolant outlet of the water-cooled exhaust manifold.

A coolant flow control apparatus may include a coolant controller housing of which an inlet for coolant to flow in, an outlet for the coolant to flow out, a first coolant supply line and a second coolant supply line are formed, a water pump mounted to the coolant controller housing for transmitting the coolant, a valve plate selectively opening/closing the first coolant supply line, a valve piston selectively opening/closing the second coolant supply line, a driving unit selectively moving the valve plate and the valve piston for closing or opening the first coolant supply line and the second coolant supply line respectively and a controller configured for controlling an operation of the driving unit.