Engine Cooling System: Other Mercury Sable IV

Cooling Fans

The cooling fans are controlled by four relays to provide three speeds. If DTC P1474, P1477 or P1479 are present, refer to SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV for diagnosis.

In HIGH speed, the cooling fans are wired parallel and the following relays are grounded by the PCM

1. Fan braking relay.
2. Engine cooling fan relay.

In MEDIUM speed, the cooling fans are wired parallel through a resistor and the following relays are grounded by the PCM

1. Fan braking relay.

In LOW speed, the cooling fans are wired in series and the following relays are grounded by the PCM

1. Fan braking relay.
2. Engine cooling fan relay.
3. HEDF and EDF relay.

Cap

1. Make sure the engine is cool.
2. Wrap a thick cloth around the coolant pressure relief cap on the coolant reservoir. Slowly turn the cap counterclockwise (left) until the pressure begins to release.
3. Step back while the pressure releases.
4. When you are sure all the pressure has been released, use the cloth to turn and remove the cap.
5. Immerse the pressure relief cap in water and install it on the shallow filler neck of Radiator/Heater Core Pressure Tester and Radiator Cap Adapter, part of Radiator/Heater Core Pressure Tester.
6. Immerse the filler neck seal in water and install it in the filler neck adapter.
7. Install the filler neck adapter with the filler neck seal to the Radiator Cap Adapter.
8. Connect the female quick-connect fitting of the pressure test pump to the male quick-connect fitting of the filler neck adapter.
9. Slowly depress the plunger of the pressure test pump until the pressure gauge reading stops increasing and note the highest pressure reading obtained.
10. Release the pressure by turning the relief screw counterclockwise. Then tighten the pressure relief screw and repeat Step 6 (at least twice) to make sure the reading is repeatable within the specifications of the pressure relief cap.
11. If the pressure test gauge readings are not within specifications, install a new pressure relief cap. If the pressure test gauge readings are within specifications, carry out the cooling system Pressure Test.

Thermostat-Water

A new water thermostat should be installed only after the following electrical and mechanical tests have been carried out.

Thermostat-Electrical Test

Note. The electrical thermostat test is most accurate if carried out indoors at less than 37.8°C (100°F) ambient air. This test may be carried out with or without the hood open and with the engine warm or cold.

1. Check the engine coolant level. Fill as needed.
2. With the ignition OFF, remove the engine coolant temperature (ECT) sensor harness connector and attach ECT Sensor "T" Cable as a jumper between the powertrain control module and the ECT Sensor. Attach the 73III Automotive Meter to the ECT Sensor "T" Cable. Voltage values (0-5 V) may now be monitored while the sensor retains its connection to the wiring harness. A Diagnostic tool or the Service Bay Diagnostic System (SBDS) may be used to monitor the ECT on vehicles equipped with data link connector (DLC). The SBDS sequence to use for the screen is: Toolbox-Electronic Engine Control and DCL-Item.
3. Place the transmission in PARK (P) or NEUTRAL (N).
4. Start the engine and allow the engine to idle throughout this test. Allow the engine to run for two minutes, then record the ECT voltage. Record the ECT voltage every 60 seconds. When the ECT voltage trend changes direction or only changes slightly (0.03 volt or less) from the previous reading, record this as the thermostat opening voltage. Use the voltage and corresponding coolant temperature chart listed below. VOLTAGE AND CORRESPONDING COOLANT TEMPERATURE Coolant Temperature °C (°F) ECT (Volts) 22 (71) 3.00 43 (109) 2.01 71 (159) 1.01 82 (180) 0.75 91 (195) 0.59 97 (206) 0.50 105 (221) 0.40
5. If the thermostat opening voltage is greater than 0.75 volt and less than 82°C (180°F), or less than 0.50 and greater than 97°C (206°F), install a new water thermostat.
6. If the thermostat opening voltage is less than 0.75 volt and greater than 82°C (180°F) or less than 0.50 and greater than 97°C (206°F), the water thermostat is good and a new thermostat should not be installed. GO to «SYMPTOM CHART»(ref-204655-S25257479932005111300000) for further instructions.

Thermostat-Mechanical Test

1. Remove the water thermostat.
2. Check the water thermostat for seating. Hold the water thermostat up to a lighted background. Leakage of light around the thermostat valve at room temperature indicates a new water thermostat should be installed. Some water thermostats have a small leakage notch at one location on the perimeter of the thermostat valve, which is considered normal.
3. Immerse the water thermostat in a boiling antifreeze and water mixture.
4. See the «SPECIFICATIONS»(ref-204655-S06623687212005111300000) chart for water thermostat opening temperatures.

Filling and Bleeding With RADKITPLUS

1. Using the special tool, install the RADKITPLUS and follow the RADKITPLUS manufacturer's instructions to fill and bleed the cooling system.

Filling Without RADKITPLUS

To maintain the integrity of the coolant and the cooling system

1. Add Motorcraft Premium Engine Coolant VC-4-A (in Oregon VC-5, in Canada CXC-10) or equivalent meeting Ford specification ESE-M97B44-A (green color), or Motorcraft Premium Gold Engine Coolant VC-7-A (in Oregon VC-7-B) or equivalent meeting Ford specification WSSM97B51- A1 (yellow color). Use the same coolant that was drained from the cooling system. Do not mix coolant types .
2. Do not add Motorcraft Specialty Engine Coolant such as VC -2 or an equivalent meeting Ford specification WSS-M97B44-D. Mixing coolants can degrade the coolant's corrosion protection .
3. 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 .
4. Do not mix with recycled coolant unless it meets the requirements of Ford specification ESEM97B44- A or WSS-M97B51-A1. Not all coolant recycling processes meet this Ford specification. Use of such coolant can harm the engine and cooling system components .

Note. The addition of Motorcraft Cooling System Stop Leak Pellets, VC-6, darkens Motorcraft Premium Gold Engine Coolant from yellow to golden tan.

Scheme 98

1. Install the front splash shield.
2. Lower the vehicle.
3. Fill the degas bottle with the correct engine coolant mixture.
4. Install the pressure relief cap.
5. Move the temperature blend selector to the full warm position.
6. Run the engine until it reaches operating temperature.
7. Add the correct engine coolant mixture to the degas bottle until the coolant level is between the COOLANT FILL LEVEL marks.
8. Turn off the engine and allow the cooling system to cool. Recheck the coolant level and fill the cooling system to the FULL mark on the degas bottle.
9. Repeat Steps 3 through 8 until the reservoir level is OK.

Bleeding Without RADKITPLUS

1. Bleed the cooling system as follows: Select the maximum heater temperature and blower motor speed settings. Position the control to discharge air from the A/C vents in the instrument panel. WARNING: Do not stand in line with or near the engine cooling fan blade when revving the engine. Start the engine and allow it to idle. While the engine is idling, feel for hot air from the A/C vents. CAUTION: If the air discharge remains cool and the engine coolant temperature gauge does not move, the engine coolant level is low in the engine and must be filled. Stop the engine, allow it to cool and fill the cooling system. Start the engine and allow it to idle until the normal operating temperature is reached. Hot air should discharge from the A/C vents. The engine coolant temperature gauge should maintain a stabilized reading in the middle of the normal range, and the upper radiator hose should feel hot to the touch. Shut the engine off and allow it to cool. Check the engine for coolant leaks. Check the engine coolant level in the degas bottle and fill it as necessary.