CYLINDER DEACTIVATION ENGINE COOLING WATER APPARATUS AND OPERATION METHOD THEREOF

PURPOSE: A variable cylinder engine cooling system and a method thereof are provided to vary the number of operable cylinders depending on various driving conditions, thereby improving fuel efficiency and enhancing cooling efficiency in order to reduce exhaust emission and additionally improve the fuel efficiency. CONSTITUTION: A variable cylinder engine cooling system and a method thereof comprise a first bank coolant circuit, a second bank coolant circuit, and a three-way thermostat(51). A power cutoff gear(12) connected to the crank shaft of a first bank(10) with plural cylinders is engaged with one portion of an output shaft which penetrates an engine cylinder block, and a power cutoff gear(22) connected to the crank shaft of a second bank(20) with other plural cylinders is engaged with the other portion of the output shaft. The first bank coolant circuit connects the first bank and a radiator(56) which cools hot coolant with heat exchange, and circulates the coolant from the first bank. The second bank coolant circuit connects the second bank and the radiator, and circulates the coolant from the second bank. The three-way thermostat and a coolant path, which connects the first bank coolant circuit and the second bank coolant circuit, form coolant paths to the radiator respectively. In the three-way thermostat, the coolant paths are separately opened and closed by an ECU(Electronic Control Unit) which controls an engine. [Reference numerals] (AA) Battery