Cooling System: Description and Operation
Engine CoolingCAUTION: Vehicle cooling systems are filled with Motorcraft Premium Gold Engine Coolant (yellow color). Always fill the cooling system with the same type of coolant that was drained from the system. Do not mix coolant types.
NOTE: The addition of Cooling System Stop Leak Pellets darkens Motorcraft Premium Gold Engine Coolant from yellow to golden tan.
The cooling system consists of the following components:
^ Block heater
^ Coolant crossover manifold assembly (4.6L, 5.4L)
^ Degas bottle
^ Fan blade
^ Mechanical fan clutch (4.2L)
^ Electronic fan clutch (4.6L, 5.4L)
^ Fan shroud
^ Radiator
^ Pressure relief cap
^ Radiator draincock
^ Upper and lower radiator hoses
^ Coolant crossover manifold assembly coolant hose
^ Coolant pump
^ Coolant thermostat
The coolant pump circulates the coolant.
The coolant thermostat:
^ controls coolant temperature.
^ allows quicker engine warm-up.
The degas bottle:
^ holds surplus coolant when hot.
^ de-aerates the system reducing hot spots.
^ is the location for service fill.
^ allows coolant expansion and system pressurization.
^ replenishes coolant to the system.
The fan blade draws air through the radiator to help cool the system coolant.
The fan clutch controls the fan speed.
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 coolant pump.
^ from the coolant pump to the engine block, the cylinder heads, heater core and positive crankcase ventilation (PCV) fittings.
^ thermostat closed, the coolant returns to the coolant pump.
^ thermostat open, the coolant flows back to the radiator for heat rejection.
CAUTION: 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.
NOTE: The addition of Cooling System Stop Leak Pellets darkens Motorcraft Premium Gold Engine Coolant from yellow to golden tan.
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 Premium Gold Engine Coolant (yellow color). Use the same type of coolant that is present in the system. Do not mix coolant types.
^ Do not add orange-colored Motorcraft 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, 4.2L:
Coolant Flow Diagram, 4.6L (2V):
Coolant Flow Diagram, 5.4L 3V:
