Cooling System: Description and Operation

Engine Cooling

NOTICE: Vehicle cooling systems are filled with Motorcraft(R) Premium Gold Engine Coolant with Bittering Agent. Always fill the cooling system with the same type of coolant that was drained from the system. Do not mix coolant types. Failure to follow these instructions may result in engine or cooling system damage.

The cooling system consists of the following components:

- Block heater (located in the lower left hand corner of the engine block)
- Coolant crossover manifold assembly (located in front of the intake manifold)
- Coolant expansion tank
- Cooling fan motor and shroud
- Radiator
- Radiator draincock (located in the lower right hand corner)
- Upper and lower radiator hoses
- Bypass coolant hose
- Coolant pump
- Coolant thermostat

The coolant pump:

- circulates the coolant.

The coolant thermostat:

- controls coolant temperature.
- allows quicker engine warm-up.

The coolant expansion tank:

- holds surplus coolant when hot.
- allows coolant expansion.
- replenishes coolant to the system.

The fan motor:

- operates only when the ignition switch is in the RUN position.
- will not operate with the ignition switch in the OFF position.

The radiator:

- cannot be serviced. Install a new radiator.
- allows excess heat to be transferred to the air.

The optional block heater:

- electrical heating element is installed in the core plug opening.
- uses a standard 110V electrical supply

- keeps the engine coolant warm during cold weather.

NOTICE: Engine coolant provides freeze protection, boil protection, cooling efficiency and corrosion protection to the engine and cooling components. In order to obtain these protections, the engine coolant must be maintained at the correct concentration and fluid level in the degas bottle. Failure to follow these instructions may result in engine or cooling system damage.

When adding engine coolant, use a 50/50 mixture of engine coolant and distilled water.

To maintain the integrity of the coolant and the cooling system:

- add Motorcraft(R) Premium Gold Engine Coolant. Use the same type of coolant that is present in the system. Do not mix coolant types.
- do not add orange-colored Motorcraft(R) Specialty Orange Engine Coolant. Mixing coolants may degrade the coolant's protection rating.
- do not add alcohol, methanol or brine or any engine coolants mixed with alcohol or methanol antifreeze. These can cause engine damage from overheating or freezing.
- do not mix with recycled coolant. Use of such a coolant may harm the engine and cooling system components.

Coolant Flow Diagram, Expedition and Navigator without Auxiliary Heater

NOTE: Black arrows indicate hot, white arrows indicate cold.











Coolant Flow Diagram, Expedition and Navigator with Auxiliary Heater

NOTE: Black arrows indicate hot, white arrows indicate cold.











Coolant Flow Diagram, Expedition EL and Navigator L with Auxiliary Heater

NOTE: Black arrows indicate hot, white arrows indicate cold.