Description And Operation
The engine cooling system is divided into two sub-systems:
- A High Temperature (HT) cooling system that controls the temperature of the engine coolant.
- A Low Temperature (LT) cooling system that controls the coolant temperature of the turbocharger system and intercoolers.
HIGH TEMPERATURE COOLING SYSTEM
The High Temperature cooling system regulates engine operating temperature. It allows the engine to reach normal operating temperature as quickly as possible, maintains normal operating temperature and prevents overheating.
The cooling system also provides a means of heating the passenger compartment and cooling the engine oil. The cooling system is pressurized and uses a centrifugal water pump to circulate coolant throughout the system. A separate and remotely mounted, pressurized coolant bottle is used.
- When the engine is cold the thermostat is closed. The cooling system has no flow through the radiator. The coolant flows through the engine, water pump, engine oil cooler, and passenger compartment heater core.
- When the engine is warm the thermostat is full open. Coolant flows through the engine, radiator, engine oil cooler, passenger compartment heater core, and water pump.
LOW TEMPERATURE COOLING SYSTEM
The Low Temperature cooling system regulates the turbocharger system components operating temperature. The low temperature cooling system includes a low temperature radiator, chiller, charge air cooler (inside intake manifold), turbocharger, low pressure coolant reservoir, and auxiliary coolant pump (PCM controlled).
| CALL OUT | DESCRIPTION |
|---|---|
| 1 | Pressure Sensor |
| 2 | Temperature Sensor |
| 3 | Humidity Sensor |
| 4 | High temperature Coolant Loop |
| 5 | Low temperature Coolant Loop |
| 6 | Transmission Oil Loop (948TE Transmission) |
| 7 | Liquid R134a or R1234yf |
| 8 | Gas R134a or R1234yf |
| 9 | Ambient Airflow |
| 10 | Ambient Air temperature Sensor |
| 11 | Automatic Transmission Oil Cooler (948TE Transmission) |
| 12 | Low Temperature Radiator |
| 13 | High Temperature (Engine) Radiator |
| 14 | Auxiliary Coolant Pump |
| 15 | Turbocharger |
| 16 | 2 mm Orifice |
| 17 | Water A/C Condenser |
| 18 | Water Charge Air Cooler |
| 19 | Engine Oil Cooler |
| 20 | A/C Pressure Sensor |
| 21 | Passenger Compartment Airflow |
| 22 | Thermostatic Expansion Valve (TXV) |
| 23 | 12 Volt Electric Cabin Heater |
| 24 | Front Heater Core |
| 25 | In-Car Temperature Sensor |
| 26 | A/C Evaporator |
| 27 | A/C Compressor |