Apparatus for adjusting temperature of oil for vehicle and method for controlling the apparatus

An apparatus for adjusting temperature of oil for a vehicle, the apparatus comprising:

• an Exhaust Gas Recirculation (EGR) valve installed on a fluid channel branching off from an exhaust pipe;
• a complex heat exchanger structured to transfer exhaust gas having passed through the EGR valve to an engine intake pipe via an EGR cooling path in which the exhaust gas having passed through the EGR valve performs heat exchange with a coolant, an oil heating path in which the exhaust gas having passed through the EGR valve performs heat exchange with the oil, and a bypass path in which the exhaust gas having passed through the EGR valve does not perform heat exchange;
• an NOx sensor installed in the exhaust pipe;
• and
• a controller that controls the complex heat exchanger in response to a signal from the NOx sensor,
• wherein the complex heat exchanger is provided with an exhaust gas passage for the exhaust gas bound for the EGR cooling path under control by the controller, a swing valve that selectively fully closes any one of exhaust gas passages for the exhaust gas bound for the oil heating path and the bypass path, and a bypass valve that opens or closes the bypass path.