An engine cooling apparatus includes a mechanical water pump having a suction hole and N discharge holes (N is an integer not less than two), N water jackets that are arranged in an engine and correspond to the N discharge holes, N joint passages, each of which joins one of the N discharge holes to the associated water jacket, a return passage that returns coolant to the suction hole after the coolant has passed through the N water jackets and has merged in a merging portion, a coolant stopping mechanism that blocks return flow of coolant through the return passage, and N communication passages each of which allows the corresponding one of the N joint passages to communicate with the suction hole while bypassing the N water jackets and the coolant stopping mechanism.