Engine Cooling System: Diagnosis Mercury Montego III

Inspection and Verification

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

1. Verify the customer's concern by operating the engine to duplicate the condition.
2. Inspect to determine if any of the following mechanical or electrical concerns apply. VISUAL INSPECTION CHART Mechanical Electrical Leaks Restricted airflow coolant through the condenser/radiator Damaged hoses Loose/damaged hose clamps Damaged gasket Damaged head gaskets Damaged intake manifold gasket Damaged coolant pump Damaged radiator Damaged degas bottle Damaged heater core Damaged engine coolant temperature (ECT) sensor Damaged wiring Electric cooling fans Fuse Fan control module Circuitry
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
4. If the cause is not visually evident, connect the diagnostic tool to the data link connector (DLC) and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle: check that the program card is correctly installed. check the connections to the vehicle. check the ignition switch position.
5. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.
6. Carry out the diagnostic tool data link test. If the diagnostic tool responds with: (appropriate communication networks, such as SCP, ISO, UBP, CAN) circuit fault; all electronic control units no response/not equipped, refer to «MODULE COMMUNICATIONS NETWORK»(ref-233024) . No response/not equipped for generic electronic module (GEM), refer to «MULTIFUNCTION ELECTRONIC MODULES»(ref-233027) . System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out the self-test diagnostics for the GEM.
7. If the DTCs retrieved are related to the concern, go to the «GENERIC ELECTRONIC MODULE (GEM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX»(ref-233003-S27807351852006052400000) .
8. If no DTCs related to the concern are retrieved, GO to the «SYMPTOM CHART»(ref-233003-S15525177552006052400000) .

Powertrain Control Module Diagnostic Trouble Code (DTC) Index

POWERTRAIN CONTROL MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX

Symptom Chart

SYMPTOM CHART

Testing

1. A1 CHECK THE ENGINE COOLANT LEVEL WARNING: Never remove the pressure relief cap while the engine is operating or when the cooling system is hot. Failure to follow these instructions can result in damage to the cooling system or engine or personal injury. To avoid having scalding hot coolant or steam blow out of the degas bottle when removing the pressure relief cap, wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly. Step back while the pressure is released from the cooling system. When you are sure all the pressure has been released, turn and remove the pressure relief cap (still with a cloth). NOTE: Allow the engine to cool before checking the engine coolant level. Key in OFF position. Visually check the engine coolant level at the degas bottle. Is the engine coolant level within specification? Yes : GO to A2. No : REFILL the engine coolant as necessary. GO to A2.
2. A2 INSPECT THE DEGAS BOTTLE PRESSURE RELIEF CAP WARNING: Never remove the pressure relief cap while the engine is operating or when the cooling system is hot. Failure to follow these instructions can result in damage to the cooling system or engine or personal injury. To avoid having scalding hot coolant or steam blow out of the degas bottle when removing the pressure relief cap, wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly. Step back while the pressure is released from the cooling system. When you are sure all the pressure has been released, turn and remove the pressure relief cap (still with a cloth). Remove the pressure relief cap. Inspect the pressure relief cap for foreign material between the sealing gasket and the diaphragm. Test the pressure relief cap. Refer to «COMPONENT TESTS»(ref-233003-S13017619442006052400000) . Is the pressure relief cap OK? Yes : Go to A3. No : CLEAN or INSTALL a new pressure relief cap. TEST the system for normal operation.
3. A3 CHECK THE ENGINE COOLANT FOR INTERNAL LEAK WARNING: Never remove the pressure relief cap while the engine is operating or when the cooling system is hot. Failure to follow these instructions can result in damage to the cooling system or engine or personal injury. To avoid having scalding hot coolant or steam blow out of the degas bottle when removing the pressure relief cap, wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly. Step back while the pressure is released from the cooling system. When you are sure all the pressure has been released, turn and remove the pressure relief cap (still with a cloth). Inspect the engine coolant in the degas bottle for signs of engine oil. Is oil evident in the coolant? Yes : If engine oil is evident, REFER to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-233008) . No : GO to A4.
4. A4 CHECK THE ENGINE FOR COOLANT Remove the oil level indicator from the engine. Is coolant evident in the oil? Yes : If coolant is in the engine, REFER to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-233008) . No : GO to A5.
5. A5 PRESSURE TEST THE ENGINE COOLING SYSTEM Pressure test the engine cooling system. Refer to the «COMPONENT TESTS»(ref-233003-S13017619442006052400000) . Does the engine cooling system leak? Yes : REPAIR or INSTALL new components. TEST the system for normal operation. No : The cooling system is operational. GO to «SYMPTOM CHART»(ref-233003-S15525177552006052400000) .

1. B1 CHECK THE ENGINE COOLANT LEVEL NOTE: If the engine is hot, allow the engine to cool before proceeding. Key in OFF position. WARNING: Never remove the pressure relief cap while the engine is operating or when the cooling system is hot. Failure to follow these instructions can result in damage to the cooling system or engine or personal injury. To avoid having scalding hot coolant or steam blow out of the degas bottle when removing the pressure relief cap, wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly. Step back while the pressure is released from the cooling system. When you are sure all the pressure has been released, turn and remove the pressure relief cap (still with a cloth). Check the engine coolant level at the degas bottle. Is the engine coolant OK? Yes : GO to B2. No : REFILL the engine coolant at the degas bottle. GO to «PINPOINT TEST A»(ref-233003-S35725898912006052400000) .
2. B2 CHECK THE COOLANT CONDITION Check the coolant for dirt, rust or contamination. Is the coolant condition OK? Yes : GO to B3. No : FLUSH the engine cooling system. REFER to «COOLING SYSTEM DRAINING, FILLING AND BLEEDING»(ref-233003-S08782495312006052400000) . TEST the system for normal operation.
3. B3 CHECK FOR AN AIRFLOW OBSTRUCTION Inspect the A/C condenser core and radiator for obstructions such as leaves or dirt. Is there an obstruction? Yes : REMOVE the obstruction. CLEAN the A/C condenser core and radiator. TEST the system for normal operation. No : GO to B4.
4. B4 CHECK THE THERMOSTAT OPERATION Key in START position. Start the engine and allow the engine to run for 10 minutes. Key in OFF position. Feel the upper and lower radiator hose. Are the upper and lower radiator hoses cold? Yes : CARRY OUT the «Thermostat»(ref-233003-S32090220232006052400000) component tests. No : GO to B5.
5. B5 CHECK THE COOLING FAN OPERATION Using the diagnostic tool, cycle the cooling fans to the HIGH and LOW positions. Do the cooling fans operate? Yes : REFER to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-233008) for diagnosis and testing of the engine. No : REFER to the «INTRODUCTION - GASOLINE»(ref-229953) article to diagnose cooling fans.

1. C1 CHECK THE ENGINE TEMPERATURE Key in START position. Start the engine and allow the engine to idle for 10 minutes. Key in OFF position. Feel the upper and lower radiator hoses. Are the upper and lower radiator hoses cold? Yes : CARRY OUT the «Thermostat»(ref-233003-S32090220232006052400000) component tests. No : REFER to «INSTRUMENT CLUSTER»(ref-233031) for diagnosis and testing of the engine coolant temperature gauge.

Pressure Test

1. Turn the engine OFF.
2. Check the engine coolant level. Refer to «COOLING SYSTEM DRAINING, FILLING AND BLEEDING»(ref-233003-S08782495312006052400000) .
3. Connect the Radiator/Heater Core Pressure Tester to the degas bottle nipple and overflow hose. Install a pressure test pump to the quick-connect fitting of the test adapter.
4. Slowly depress the plunger of the pressure test pump until the pressure gauge reading stops increasing and note the highest pressure reading obtained.
5. If the pressure relief cap does not hold pressure, remove and wash the pressure relief cap in clean water to dislodge all foreign particles from the gaskets. Check the sealing surface in the filler neck.
6. Pressure check the pressure relief cap. If 89 kPa (13 psi) cannot be reached or if more than 124 kPa (18 psi) show on the gauge, install a new pressure relief cap.
7. Pressurize the engine cooling system as described in Step 4 (using a pressure relief cap that operates within the specified upper and lower pressure limits). Observe the gauge reading for approximately 2 minutes; refer to «GENERAL SPECIFICATIONS»(ref-233003-S25523693962006052400000) . Pressure should not drop during this time.
8. Release the system pressure by loosening the pressure relief cap. Check the engine coolant level and replenish, if necessary, with the correct engine coolant mixture. Refer to «COOLING SYSTEM DRAINING, FILLING AND BLEEDING»(ref-233003-S08782495312006052400000) .

Radiator Leak Test, Removed From the Vehicle

Note. Clean the radiator before leak testing to avoid contamination of tank.

1. Leak-test the radiator in clean water with 138 kPa (20 psi) air pressure.