Principles Of Operation - Fuel and Turbocharger Cooling System

Fuel and Turbocharger Cooling System







Principles of Operation

The fuel and turbocharger cooling system is designed to remove some of the heat added by the high-pressure common rail fuel-injection system. The high-pressure common rail fuel-injection system uses fuel for lubrication and cooling, as well as being the working medium to create the high pressure. This adds a significant amount of heat to the fuel. The fuel cooling system is designed to keep the high-pressure pump inlet and fuel tank return below 70°C (158°F). The coolant pump is turned on by the PCM when it receives a signal from the fuel temperature sensor indicating the fuel temperature in the fuel filter module has reached 35°C (95°F). The PCM turns off the coolant pump when it receives a signal from the fuel temperature sensor indicating the fuel temperature is below 20°C (68°F). The coolant pump will be on under most operating conditions.

The fuel and turbocharger cooling system is also designed to remove some of the heat being transferred to the turbocharger actuator during engine operation and after engine shut-down. The system assists in limiting the temperature exposure to the turbocharger actuator electronics. The electric coolant pump can run up to 10 minutes after the vehicle has been shut off. This is to remove some of the heat in the turbocharger actuator following engine shut-down.

It is important to make sure the fuel and turbocharger cooling system is bled correctly and the coolant level maintained for optimum performance.