A vehicle cooling system includes an internal combustion engine, a transmission having a cooler, a coolant pump, a first coolant loop, a second coolant loop, and a flow regulator. The first coolant loop fluidly connects the coolant pump to the engine and returns to the coolant pump. The second coolant loop fluidly connects the coolant pump to the transmission cooler and returns to the coolant pump, bypassing the engine. The flow regulator is configured to selectively restrict coolant flow through the second coolant loop.