Operation - Engine Cooling System

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.

When Engine is cold: Thermostat is closed, cooling system has no flow through the radiator. The coolant flows through the engine, heater core, coolant bottle and an internal engine by-pass.
When Engine is warm: Thermostat is open, coolant flows through the radiator, heater core, coolant bottle 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 coolant flow circuit is shown in (Figure).