Cooling System: Description and Operation

Engine Cooling

NOTICE: The engine cooling system is filled with Motorcraft(R) Specialty Green Engine Coolant. Mixing coolant types degrades the corrosion protection of Motorcraft(R) Specialty Green Engine Coolant.

NOTICE: Genuine Mazda(R) Extended Life Coolant and Motorcraft(R) Specialty Green Engine Coolant are very sensitive to light. Do NOT allow these products to be exposed to ANY LIGHT for more than a day or two. Extended light exposure causes these products to degrade.

NOTE: Stop-leak style pellets/products must not be used as an additive in this engine cooling system. The addition of stop-leak style pellets/products can clog or damage the cooling system, resulting in degraded cooling system performance and/or failure.

The cooling system components are the:

- block heater (if equipped).
- radiator.
- bypass tube.
- pressure relief cap.
- degas bottle.
- radiator draincock.
- coolant pump.
- engine coolant temperature indicator unit.
- thermostat (cold side).
- variable speed fan motor assembly.
- Fan Control (FC) module.
- engine block coolant weep hole.





The coolant pump is located under the engine front cover mounted to the block. A weep hole is provided on the front left side of the engine behind the generator. It is adjacent to a 13.5 mm (0.531 in) cup plug. This plug and weep hole create a reservoir for normal coolant seepage and evaporation. Every coolant pump will have some leakage past the dynamic mechanical seal. Dampness and crusting around the weep hole is acceptable and an expected result of normal engine operation. Coolant spray or leakage amounts great enough to puddle should be addressed.

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:

- add Motorcraft(R) Specialty Green Engine Coolant.
- do not add/mix different coolant types. Mixing coolants may degrade the coolant's corrosion protection.
- 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.
- Ford Motor Company does NOT recommend the use of recycled engine coolant in vehicles originally equipped with Motorcraft(R) Specialty Green Engine Coolant since a Ford-approved recycling process is not yet available.


Coolant Flow Diagram - 3.7L

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












Coolant Flow Diagram - 3.5L Gasoline Turbocharged Direct Injection (GTDI)

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