M11 Series – Service Manual – 008-065   Torque Converter Cooler

The coolant flow to provide torque converter cooling is achieved in different manners.

M11 engines use a torque converter cooler disc inside the coolant bypass hose to direct engine coolant to the inlet side of the torque converter cooler. The disc functions as follows:

• Closed Thermostat: Coolant flows from the engine through the thermostat housing and down the bypass hose. The disc directs coolant to the inlet side of the torque converter cooler.
• Open Thermostat: Coolant flows from the engine through the thermostat to the radiator out from the radiator to the torque converter cooler to the water pump inlet. The disc prevents reverse flow around the torque converter cooler to the bypass hose and then to the water pump.