Engine Cooling System: Other Mercury Montego III

Material

MATERIAL CHART

Cooling Fans

The cooling fans are controlled by a fan control module. The fan control module receives a variable signal from the powertrain control module (PCM). If DTC P0480 is present, refer to the INTRODUCTION - GASOLINE article for diagnosis.

Possible causes

1. Radiator
2. Thermostat housing assembly
3. Throttle body adapter heating
4. Coolant pump seal
5. Radiator hoses
6. Heater hoses
7. Heater core
8. Engine gaskets
9. Degas bottle

1. Low coolant level
2. Thermostat
3. Airlock in the system
4. Coolant pump
5. Internal engine coolant leak
6. Radiator
7. Radiator airflow obstruction
8. Cooling fan
9. Pressure relief cap

1. Thermostat

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 «Pressure Test»(ref-233003-S34074496992006052400000) .

Thermostat

A new thermostat should be installed only after the following thermostat 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, attach the 73III Automotive Meter to the engine coolant temperature (ECT) Sensor. 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. 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 2 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. DIAGNOSIS PROCEDURE Coolant Temperature °C (°F) ECT (Volts) 20 (68) 3.14 45 (113) 2.98 70 (158) 1.08 75 (167) 0.94 82 (180) 0.75 90 (194) 0.64 95 (202) 0.53 100 (212) 0.49 105 (221) 0.43
5. If the thermostat opening voltage is greater than 0.94 volt and less than 75°C (167°F), or less than 0.53 and greater than 95°C (202°F), install a new thermostat.
6. If the thermostat opening voltage is less than 0.75 volt and greater than 82°C (180°F) or greater than 0.50 volt and less than 97°C (206°F), the thermostat is good and a new thermostat should not be installed. GO to «SYMPTOM CHART»(ref-233003-S15525177552006052400000) for further instructions.

Thermostat - Mechanical Test

1. Remove the thermostat housing.
2. Immerse the thermostat housing and thermostat in a boiling antifreeze and water mixture.
3. See the «GENERAL SPECIFICATIONS CHART»(ref-233003-S25523693962006052400000) for thermostat opening temperatures.

MATERIAL CHART

Filling and Bleeding with RADKITPLUS

Note. For vehicles equipped with an optional rear heater, RADKITPLUS must be used whenever the underbody coolant lines and/or rear heater core are drained or removed.

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

Filling and Bleeding without RADKITPLUS

Note. For vehicles equipped with an optional rear heater, RADKITPLUS must be used whenever the underbody coolant lines and/or rear heater core are drained or removed.

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

1. Fill the degas bottle with the correct engine coolant mixture to the degas bottle seam line.
2. Install the pressure relief cap.
3. Remove the retaining clip and the fill tab on the top of the thermostat housing and fill through the thermostat housing until full.
4. Install the fill tab and retaining clip.
5. 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.
6. Start the engine and allow it to idle until engine reaches normal operating temperature. While the engine is idling, feel for hot air from the A/C vents.
7. Run the engine at 3,000 rpm for 10 minutes. 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 to the seam line.

MATERIAL CHART

1. To remove rust, sludge and other foreign material from the cooling system, use cooling system flush that is safe for use with aluminum radiators. For additional information, refer to «SPECIFICATIONS»(ref-233003-S28631208832006052400000) . This cleaning restores cooling system efficiency and helps prevent overheating. A pulsating or reversed direction of flushing water will loosen sediment more quickly than a steady flow in the normal coolant flow direction. In severe cases where cleaning solvents will not clean the cooling system efficiently, it will be necessary to use the pressure flushing method using cooling system flusher. Dispose of old coolant and flushing water contaminated with antifreeze and cleaning chemicals in accordance with local, state or federal laws.
2. Drain the cooling system. For additional information, refer to «COOLING SYSTEM DRAINING, FILLING AND BLEEDING»(ref-233003-S08782495312006052400000) .
3. Remove the radiator. For additional information, refer to «RADIATOR»(ref-233003-S08849861972006052400000) .
4. Backflush the radiator with the radiator in an upside-down position with a high-pressure hose in the lower hose location and backflush.
5. Remove the thermostat. For additional information, refer to «THERMOSTAT»(ref-233003-S32090220232006052400000) .
6. Backflush the engine. Position the high-pressure water hose into the engine through the engine return and backflush the engine.
7. Fill the cooling system. For additional information, refer to «COOLING SYSTEM DRAINING, FILLING AND BLEEDING»(ref-233003-S08782495312006052400000) .

Scheme 13

MATERIAL CHART

MATERIAL CHART

MATERIAL CHART

Scheme 14

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