Cooling System: Description and Operation

"Walter C. Avrea, the owner of patents 3, 601, 181 and RE 27, 965, has granted Ford Motor Company rights with respect to cooling systems covered by these patents."

WARNING: TO AVOID THE POSSIBILITY OF PERSONAL INJURY OR DAMAGE TO THE VEHICLE, DO NOT OPERATE THE ENGINE WITH THE HOOD OPEN UNTIL THE FAN BLADE HAS BEEN EXAMINED FIRST FOR POSSIBLE CRACKS AND SEPARATION.

WARNING: NEVER REMOVE THE PRESSURE RELIEF CAP UNDER ANY CONDITIONS WHILE THE ENGINE IS OPERATING. FAILURE TO FOLLOW THESE INSTRUCTIONS COULD RESULT IN DAMAGE TO THE COOLING SYSTEM OR ENGINE AND/OR PERSONAL INJURY. TO AVOID HAVING SCALDING HOT COOLANT OR STEAM SLOW OUT OF THE COOLING SYSTEM, USE EXTREME CARE WHEN REMOVING THE PRESSURE RELIEF CAP FROM A HOT COOLING SYSTEM. WAIT UNTIL THE ENGINE HAS COOLED, THEN WRAP A THICK CLOTH AROUND THE PRESSURE RELIEF CAP AND TURN IT SLOWLY UNTIL PRESSURE BEGINS TO RELEASE. STEP BACK WHILE THE PRESSURE IS RELEASED FROM THE COOLING SYSTEM. WHEN CERTAIN ALL THE PRESSURE HAS BEEN RELEASED, PRESS DOWN ON PRESSURE RELIEF CAP (STILL WITH A CLOTH), TURN AND REMOVE PRESSURE RELIEF CAP.

The cooling system includes the following:
^ radiator
^ water thermostat
^ water pump
^ engine cooling fan motor
^ the degas bottle located on the right side of engine compartment helps maintain the correct volume of engine coolant.

3.0L (2V) and 3.0L (4V) Engines
The water pump has a conventional design and is driven by the drive belt.

3.4L SHO Engine
The water pump on the 3.4L SHO engine is a modular design mounted on the LH cylinder head. It is driven by a separate drive belt.
The water thermostat is located in the water pump housing inlet which is attached to the LH cylinder head.

Electrical System

NOTE: With A/C ON, the cooling fan motors will run continuously. Cooling fan motors will not cycle ON and OFF with A/C clutch.

NOTE: An exception to this is when vehicle speed is over 61 km/h (38 mph) and coolant temperature is below 100°C (212°F), and A/C head pressure is below 1.71 MPA (250 psi). The cooling fan motors will then automatically shut off.

The cooling fan motors are mounted within a fan shroud behind the radiator.

Coolant Recovery System

NOTE: When the water thermostat is closed, coolant flows through the degas tube and hose assembly from the lower radiator hose to the degas bottle.

Trapped air in the cooling system must be removed. A pressurized degas bottle system is used which continuously separates the air from the cooling system.
^ When the water thermostat is open, coolant flows through both the small hose from the top of the radiator outlet tank and the degas tube and hose assembly from the engine to the degas bottle.
^ The degas bottle separates any trapped air from the coolant and replenishes the system through its degas hose.
^ The degas bottle serves as the location for:
^ service fill.
^ coolant expansion during warm-up.
^ system pressurization from the pressure relief cap.
^ air separation during operation.
^ The degas bottle is designed to have approximately 0.5-1 liter (0.53-1.06 quarts) of space when cold to allow for coolant expansion.
^ Use Ford Extended Life Engine Coolant F6AZ-19544-AA or an equivalent DEX-COOL coolant meeting Ford specification WSS-M971344-D.
^ Do not add conventional green coolant or recycled coolant to your vehicle if originally equipped with orange coolant.

Radiator-Aluminum Core, Crossflow

NOTE: Whenever leaks or damage to the radiator are found, the entire radiator must be replaced as an assembly.

The radiator is of the tube-and-louvered fin core type with the tubes arranged horizontally for crossflow of the coolant.
^ Two radiator tanks, one on each side of the radiator, provide uniform distribution of the coolant through crossflow tubes.
^ The radiator tank on the LH side of the radiator contains a cooler for cooling the automatic transmission fluid.
^ The crossflow radiator has an aluminum core with nylon tanks.
^ The radiator requires special service procedures different from copper/brass core radiators.

Cooling Fan, Electric

WARNING: THE ENGINE ELECTRIC COOLING FAN MOTOR MAY COME ON AT ANY TIME WITHOUT WARNING WITH THE IGNITION SWITCH IN THE RUN POSITION, EVEN IF THE ENGINE IS NOT RUNNING.

The fan control system consists of the following:
^ Powertrain Control Module (PCM)
^ related wiring
^ two, two-speed cooling fan motors attached to a fan shroud located behind the radiator
^ powertrain control module
^ A/C cycling switch
^ A/C clutch coil circuit
^ cooling fan motors
The cooling fan motors are wired to operate only when ignition switch is in the RUN position, thereby preventing radiator electric motor operation after the ignition switch is turned to the OFF position.

Thermostat, Water
When the coolant is cold, the water thermostat is in the closed position and the coolant flow is limited to the cylinder block, cylinder head heater system and the degas bottle.
As the engine coolant temperature increases, the water thermostat opens and allows a portion of the coolant to pass into the radiator.

3.0L (2V) Engine
The water thermostat is located in the water hose connection which is attached to the rear of the lower intake manifold.

3.0L (4V) Engine
The water thermostat is located in the water thermostat housing which is attached to the A/C compressor brace on the left side of the engine.

3.4L SHO Engine
The water thermostat is located in the thermostat housing which is attached to the water pump on the RH side of the engine.

Block Heater
The block heater is designed to keep the engine coolant warm during cold weather to aid in cold starting and consists of:
^ electrical heating element installed in the core plug opening in the cylinder block.
^ electrical cable which plugs into a standard 110-volt AC electrical outlet.