Cooling System: Description and Operation
Engine Cooling
NOTICE: Always fill the cooling system with the same type of coolant that is present in the system. Do not mix coolant types. Mixing coolant types can result in cooling system damage.
The cooling system components include the following:
- Block heater (mounted in the RH side at the rear of the engine block)
- Fan blade
- Fan clutch
- Fan shroud
- Radiator
- Degas bottle
- Pressure relief cap
- Radiator draincock
- Coolant pump
- Coolant thermostat
- Oil filter adapter
- Upper radiator hose
- Lower radiator hose
- Degas bottle supply hose
- Fan stator - 6.4L
- EGR coolers - 6.4L (located on LH side of engine and front cover)
- Engine oil cooler - 6.4L (located under the intake manifold)
- Heater core
- Heater hoses
- Venturi tee - 6.4L
NOTICE: A correctly installed venturi tee is important to normal cooling system function. Installing a standard tee or installing a venturi tee incorrectly can cause cooling system damage.
NOTICE: Do not remove the venturi tee from the cooling system, removing the venturi tee can cause cooling system damage.
On vehicles equipped with a 6.4L diesel engine, a venturi tee is used to prevent the reverse flow of cool air and coolant from the degas bottle to the radiator.
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.
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:
- NOTICE: With the engine cold, fill vehicles to within the cold fill range shown on the degas bottle. This fill level will allow for coolant expansion. Overfilling the degas bottle may result in damage to the pressure cap, which can cause the engine to overheat.
Add Motorcraft(R) Premium Gold Engine Coolant with Bittering Agent or equivalent (yellow color). Do not mix coolant types.
- Do not add/mix orange-colored Motorcraft(R) Specialty Orange Engine Coolant with Bittering Agent (US) Motorcraft(R) Extended Life Engine Coolant (Canada); or equivalent. Mixing coolants may degrade the coolant's corrosion protection.
- Do not add alcohol, methanol, 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 coolants may harm the engine and cooling system components. Do not mix coolant types.
NOTICE: Inadequate concentration of Motorcraft(R) Diesel Cooling System Additive may result in major corrosive damage to the engine cooling system components. An excessive amount of additive may cause formation of gels that may cause coolant flow restriction, plugging of passages and overheating.
For vehicles equipped with a diesel engine, use Motorcraft(R) Diesel Cooling System Additive as specified in the diesel engine coolant test. Motorcraft(R) Diesel Cooling System Additive provides additional long-term protection against cavitation erosion and corrosion beyond that provided by the engine coolant. Check the nitrite level and freeze protection as recommend in the maintenance schedule and maintain the correct level of Motorcraft(R) Diesel Cooling System Additive in the cooling system. Refer to Coolant Test - Diesel Engine Coolant Test.
Coolant Flow Diagram, 5.4L (3V)
NOTE: Black arrows indicate hot, white arrows indicate cold.
Coolant Flow Diagram, 6.8L (3V)
NOTE: Black arrows indicate hot, white arrows indicate cold.
Coolant Flow Diagram, 6.4L Diesel
NOTE: Black arrows indicate hot, white arrows indicate cold.
