Cooling System: Description and Operation

The cooling system components are:
- block heater.
- Engine Coolant Temperature Sensor (ECT sensor).
- fan blade.
- fan clutch.
- fan shroud.
- radiator.
- radiator cap.
- radiator coolant recovery reservoir.
- radiator draincock.
- water temperature indicator sender unit.
- water thermostat and gasket assembly (4.2L).
- water thermostat (4.6L, 5.4L).
- the radiator allows excess engine heat to be transferred to the air.
- upper radiator hose.
- lower radiator hose.

The water pump circulates the coolant.

The water thermostat:
- controls coolant temperature.
- allows quicker engine warm-up.

The degas bottle
- holds surplus coolant when hot.
- de-aerates the system reducing engine hot spots.
- location for service fill.
- allows coolant expansion and system pressurization [110 kPa (16 psi)].
- air separation during operation.
- replenishes coolant to system.

The fan blade draws air through the radiator to help cool the system coolant.

The fan clutch is a thermostatic-controlled clutch that controls the fan drive.

Coolant flow is as follows:

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

The engine coolant flows:
- from the lower radiator hose to the water pump.
- from the water pump to the engine block and the cylinder heads.
- thermostat closed, the coolant returns to the water pump.
- thermostat open, the coolant flows back to the radiator.
- to the radiator for heat rejection the back to the lower radiator hose.

Recycled coolant: use recycled engine coolant produced by Ford approved processes. Not all coolant recycling processes produce coolant which meets Ford specification ESE-M97B44-A, and use of such a coolant may harm engine and cooling system components.

Unsatisfactory coolant materials:
- alcohol-type antifreeze does not provide adequate water pump lubrication.
- has a lower boiling point.
- provides reduced antifreeze protection.
- alkaline brine solutions will cause serious engine cooling system damage.

The water temperature indicator sender unit provides a signal to the temperature gauge.

The block heater:
- is an optional electrical heating element installed in core plug opening.
- uses a standard 110 v electrical supply.
- keeps the engine coolant warm during cold weather.