Coolant control valve unit, and engine cooling system having the same

An engine cooling system, comprising:

• a cylinder head disposed on a cylinder block;
• and
• a coolant control valve unit disposed at a coolant outlet of the cylinder head and to which coolant discharged from the cylinder head and the cylinder block is supplied and distributing the supplied coolant to coolant components,
• wherein the coolant control valve unit includes:
• a valve housing including at least a first passage and a second passage in which the coolant flows and disposed at a predetermined position;
• a first valve and a second valve provided to open and close the first and second passages;
• a first stem and a second stem respectively connected with the first valve and the second valve and extending to movement directions of the first valve and the second valve;
• a driving plate of which one surface is connected with end portions of the first stem and the second stem;
• and
• an actuator pushing and pulling the driving plate to allow the first valve and the second valve to open and close the first passage and the second passage,
• wherein the first passage and the second passage respectively have a first length and a second length which are predetermined such that initially the first passage is opened and then the second passage is opened while the actuator lifts the first valve and the second valve by the driving plate.