Cougar/T-Bird Cooling System


The engine cooling system operates in the following manner:

  • Engine coolant flows through the radiator tubes and is cooled by air passing over the cooling fins assisted by the cooling fan or fans (depending upon application).
  • Coolant is then circulated from the radiator outlet tank through the water pump and into the cylinder block to complete the circuit.
  • Coolant expands as the temperature and pressure rise in the cooling system. When the limiting system working pressure is reached, the    pressure relief valve in the pressure relief cap is lifted from its seat and allows coolant to flow through the radiator overflow hose into the radiator coolant recovery reservoir.
  • The pressure relief cap has a rubber seal on the underside to prevent leakage.
  • When cooling system temperature and pressure drop, the coolant contracts in volume, reducing pressure in the radiator. Coolant in the  radiator coolant recovery reservoir will then flow back into the radiator through the vacuum relief valve in the pressure relief cap.
  • The constant control relay module (CCRM) activates the cooling fan motor when coolant or engine reach a specified temperature.
  • On vehicles equipped with air conditioning, the cooling fan motor is activated whenever the A/ C clutch is engaged.

    • Item
    Description
    Item
    Description
    1
    Radiator Support
    9
    Battery Ground Cable
    2
    Upper Radiator Hose
    10
    Radiator Overflow Hose
    3
    Bolt (2 Req'd)
    11
    Front Fender Apron
    4
    Cooling Fan, Motor & Shroud Assembly
    12
    Grommet
    5
    Lower Radiator Hose
    13
    Bolt (3 Req'd)
    6
    Screw (2 Req'd)
    14
    U-nut (2 Req'd)
    7
    Radiator Coolant Recovery Reservoir
    (located on opposite side for '89-'93 SC)
    15
    Auxillary Cooling Fan
    ('94-'95 SC only)
    8
    Radiator

    Electrical System

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

    NOTE: An exception to this is when vehicle speed is over 72 km/ h (45 mph) and coolant temperature is below 104 *C (220 *F). The cooling fan motor will then automatically shut off.

    The cooling fan motor is mounted within a shroud behind the radiator. On vehicles equipped with 3.8L SC engine, an auxiliary cooling fan motor is mounted in front of the radiator. The constant control relay module (CCRM) actuates the cooling fan motor or motors (depending upon application) when:

  • The coolant reaches a specified temperature.
  • When the engine reaches a specified speed.
  • When the A / C clutch is activated (if equipped).

    • Coolant Recovery System

    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 BLOW OUT OF THE RADIATOR (8005), USE EXTREME CARE WHEN REMOVING THE PRESSURE RELIEF CAP FROM A HOT RADIATOR. WAIT UNTIL THE ENGINE HAS COOLED, THEN WRAP A THICK CLOTH AROUND THE PRESSURE RELIEF CAP AND TURN IT SLOWLY TO THE FIRST STOP. STEP BACK WHILE THE PRESSURE IS RELEASED FROM THE COOLING SYSTEM. WHEN CERTAIN ALL PRESSURE HAS BEEN. RELEASED, PRESS DOWN ON@THE PRESSURE RELIEF CAP: (STILL WITH A CLOTH), TURN AND REMOVE IT.

    The coolant recovery system operates as follows:

    The system uses a 100 kPa (16 psi) pressure relief cap a plastic radiator coolant recovery reservoir and radiator overflow hose .

    When coolant in radiator expands to the overflow point, it passes through the pressure relief cap and into the radiator coolant recovery reservoir. When coolant in radiator cools down and contracts, it pulls coolant from the radiator coolant recovery reservoir through a spring-loaded vacuum relief valve in the pressure relief cap and back into the radiator.

  • Extra coolant is carried in the radiator coolant recovery reservoir.
  • Any air bubbles trapped in the cooling system are vented in the radiator coolant recovery reservoir.

    • Radiator

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

    Aluminum Core, Crossflow

    The crossflow radiators used in base 3.8L and 4.6L model Thunderbird, Cougar vehicles:

  • Are an aluminum tube and louvered fin-core design with tubes arranged horizontally for crossflow of the engine coolant.
  • Have two tanks, one on each side of the radiator, that provide uniform coolant distribution to the crossfiow tubes.
  • Have an integral transmission oil cooler in the tank on the left side of the radiator for cooling the transmission fluid on automatic transmission-equipped vehicles.
  • Are equipped with a coolant recovery system.

    • Copper/Brass Core, Downflow

    The radiator used on vehicles equipped with a 3.8L SC engine has the following features:

  • A copper/ brass tube and louvered f in-core design with tubes arranged vertically for downflow of the coolant.
  • The tank at the top of the radiator provides uniform coolant distribution to the core downflow tubes.
  • The tank at the bottom of the radiator receives engine coolant from the downflow tubes and contains an integral transmission oil cooler for cooling automatic transmission fluid.
  • Is equipped with a coolant recovery system.
  • The downflow radiator has an integral radiator support with an opening for air intake. An air duct is attached to the radiator support opening to provide air to the supercharger charge air cooler (CAC)

    • Cooling Fan, Electric

    The cooling fan system:

  • Consists of a fan blade and a two-speed cooling fan motor attached to a fan shroud located behind the radiator.
  • The cooling fan motor is wired to operate only when the ignition switch is in the ON position. This prevents the cooling fan motor from operating after the ignition switch is turned to the OFF position.
  • The cooling fan motor is serviced only as an assembly with the fan blade and the fan shroud.

    • Thermostat, Water

    The water thermostat operates as follows:

  • When coolant is cold, the water thermostat is in the closed position and engine coolant flow is restricted to the cylinder block, cylinder head, intake manifold and heater core.
  • As temperature increases, the water thermostat opens and a portion of the coolant is allowed to pass into the radiator.

    • Constant Control Relay Module

    WARNING: DISCONNECT THE COOLING FAN MOTOR PRIOR TO PERFORMING ANY UNDERHOOD SERVICE SINCE THE COOLING FAN MOTOR COULD CYCLE IF THE IGNITION SWITCH IS LEFT IN THE ON POSITION EVEN THOUGH THE ENGINE IS NOT RUNNING.

    NOTE: Cooling fan motor will not cycle with A/C clutch. The cooling fan motor will c6me on When A/ C switch is turned ON.

    The cooling fan motor is controlled during vehicle operation by the constant control relay module (CCRM) and powertrain control module (PCM), which will energize the cooling fan motor under the following conditions:

    Cooling fan motor will run at low speed:

  • If engine temperature is higher than normal. Cooling fan motor starts running at 106 *C (222 *F) and stops running at 101 *C (214 *F).
  • If A / C is on and vehicle speed does not provide enough natural airflow. Cooling fan motor starts running at speeds at or below 69 km/ h (43 mph) and stops running at 77 km/ h (48 mph).

    • Cooling fan motor will run at high speed:

  • If engine temperature is higher than desirable and cooling fan motor has been operating at a low speed.
  • At 109 *C (228 *F) and stops running at 105 *C (220 *F).

    • The wide-open throttle (WOT) A/C cutout is used on supercharged engine applications. During hard acceleration, a signal is sent to the powertrain control module. The powertrain control module then signals the constant control relay module to cut off power to the A/C clutch field coil. This keeps the engine from being overloaded.