Service Information: Operation

CAUTION: The cooling system is designed to function with a 50/50 mixture of Mopar® Antifreeze/Coolant, 5 Year/100, 000 Mile Formula (MS-9769) or equivalent, and distilled water. Higher concentrations may result in poor cooling performance and premature water pump seal failure. This antifreeze/coolant may not be mixed or substituted with any other type.

Fig 1: Identifying Cooling System Operation

Courtesy of DAIMLERCHRYSLER CORP.

1 - COOLANT RESERVOIR

2 - ENGINE BLOCK

3 - HEATER CORE

4 - COOLANT CIRCULATION VALVE

5 - COOLANT CIRCULATION PUMP

6 - THERMOSTAT

7 - RADIATOR

When engine (2) is cold: Thermostat (6) is closed, cooling system has no flow through the radiator (7). The coolant flows through the engine, heater core (3), coolant recovery reservoir (1), and an internal engine by-pass.
When engine (2) is warm: Thermostat (6) is open, coolant flows through the radiator (7), heater core (3), coolant recovery reservoir (1), and by-pass.

The cooling systems primary purpose is to maintain engine temperature in a range that will provide satisfactory engine performance and emission levels under all expected driving conditions. It also provides hot coolant for heater, and cooling for automatic transmission fluid. It does this by transferring heat from engine metal to coolant, moving this heated coolant to the radiator, and then transferring this heat to the ambient air. The cooling system is also equipped with an additional electric coolant circulation pump. The pump is used to keep the passenger cabin warm by circulating coolant through the heater core when the engine is off.

Fig 2: Cooling System Operation

Courtesy of DAIMLERCHRYSLER CORP.

1 - COOLANT RESERVOIR

2 - CHARGE AIR COOLER

3 - CHARGE AIR COOLER RADIATOR

4 - CHARGE AIR COOLER CIRCULATION PUMP

Supercharged vehicles (if equipped) have additional cooling system components. The Charge Air Cooler (2), Charge Air Cooler Radiator (3), Charge Air Cooler Circulation Pump (4), and all related hoses make up the charge air cooler cooling system. The charge air cooler system operates independent of the engine cooling system. The Charge Air Cooler Circulation Pump is mounted to the side of the Charge Air Cooler Radiator. The pump is used to circulate coolant between the Charge Air Cooler and the Charge Air Cooler Radiator. The only common link between the two systems is the Coolant Recovery Reservoir (1). Both systems use the coolant reservoir as their source of coolant.