Engine Cooling System: Diagnosis Ford Expedition III

Inspection and Verification

Note. The engine cooling system is filled with Motorcraft® Premium Gold Engine Coolant. Mixing coolant types degrades the corrosion protection of Motorcraft® Premium Gold Engine Coolant.

1. Verify the customer concern.
2. Visually check the engine coolant level at the degas bottle when the system is cold.
3. Make sure the pressure relief cap is installed correctly.
4. Record any cooling system DTCs retrieved. Refer to the «DTC CHART»(ref-364096-S19666727902010062700000) for DTC descriptions.
5. If the system coolant is filled correctly and no DTCs associated with fail-safe cooling are retrieved, verify the customer's concern by operating the engine to duplicate the condition.
6. Inspect to determine if any of the following mechanical or electrical concerns apply. VISUAL INSPECTION CHART Mechanical Electrical Leaks or weeps at: Hoses Tubes Clamp joints Gaskets O-rings Thermostat housing Radiator Pressure relief cap Coolant pump Heater core (wet floor or coolant odor in vehicle) Coolant crossover manifold assembly Oil filter adapter Coolant expansion tank Cylinder block core plugs Cylinder head core plugs Block heater (if equipped) Inoperative or damaged: Wiring, connectors or PCM Electric cooling fan Cylinder Head Temperature (CHT) sensor Vehicle Speed Sensor (VSS) VISUAL INSPECTION CHART Mechanical Electrical Cracked or damaged: Hoses Tubes Hose clamps Thermostat housing Radiator Pressure relief cap Cooling fan Coolant pump Coolant expansion tank Oil filter adapter Coolant crossover manifold assembly Cylinder block core plugs Cylinder head core plugs Block heater (if equipped) Restricted airflow through the A/C condenser/radiator Drive belt loose, worn or installed incorrectly Broken or weak drive belt tensioner Excessive white or light gray exhaust smoke (may have burnt coolant odor) Coolant in engine oil Engine oil in coolant Coolant in automatic transmission fluid Automatic transmission fluid in coolant
7. If the inspection reveals an obvious concern that can be readily identified, repair it as necessary. Test the system for normal operation.
8. Inspect the coolant condition. Inspect the coolant color. If Motorcraft® Premium Gold Engine Coolant has a clear or pale yellow color, this indicates higher water content than required. Test the engine coolant freezing point range with the Coolant/Battery Refractometer. The freezing point should be in the range -45°C to -23°C (-50°F to -10°F). If the vehicle is driven in cold climates less than -36°C (-34°F), it may be necessary to increase the coolant concentration to get adequate freeze protection. Recommended coolant concentration is 50/50 ethylene glycol to distilled water. A pale green color indicates incorrect coolant (green in color) may have been added to the system. Use of incorrect (green in color) coolant degrades the corrosion protection of Motorcraft® Premium Gold Engine Coolant. Flush the system and refill with the correct mixture of distilled water and Motorcraft® Premium Gold Engine Coolant. NOTE: If Cooling System Stop Leak Pellets are used, darkening of the Motorcraft® Premium Gold Engine Coolant from yellow to golden tan will occur. Dark brown could indicate a commercially available stop leak may have been used. Flush the system and refill with the correct mixture of distilled water and Motorcraft® Premium Gold Engine Coolant. A light or reddish brown color indicates that rust may be present in the cooling system. Flush the system and refill with the correct mixture of distilled water and Motorcraft® Premium Gold Engine Coolant. An iridescent sheen on top of the coolant could indicate a trace of oil is entering the system. For information on engine diagnosis, refer to «ENGINE SYSTEM - GENERAL INFORMATION»(ref-364043) . A milky brown color may indicate that engine oil is entering the cooling system. Pressure test the cooling system. Refer to «COMPONENT TESTS»(ref-364096-S01123145002010062700000) . If engine oil is suspected, the cause of the leak may be internal to the engine. Refer to «ENGINE SYSTEM - GENERAL INFORMATION»(ref-364043) . A red, orange or light green colored sheen on top of the coolant may indicate that transmission fluid is entering the cooling system. The cause may be a leaky radiator. Pressure test the cooling system. Refer to the «COMPONENT TESTS»(ref-364096-S01123145002010062700000) . If the engine coolant appearance is acceptable, test the engine coolant freezing point range with the Coolant/Battery Refractometer. The freezing point should be in the range -45°C to -23°C (-50°F to -10°F). If the vehicle is driven in cold climates less than -36°C (-34°F), it may be necessary to increase the coolant concentration to get adequate freeze protection. Recommended coolant concentration is 50/50 ethylene glycol to distilled water. Maximum coolant concentration is 60/40 for cold weather areas. Minimum coolant concentration is 40/60 for warm weather areas. Adjust coolant range and level if necessary: If coolant is low, add specified coolant mixture only. If the engine coolant tests too weak, remove some of the engine coolant and add undiluted engine coolant until the readings are within acceptable levels. If the engine coolant tests strong, remove some of the engine coolant and add distilled water until the readings are within acceptable levels.
9. If an obvious cause for an observed or reported concern is found, correct the cause and test the system for normal operation before proceeding to the next step.
10. If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).
11. If the scan tool does not communicate with the VCM : check the VCM connection to the vehicle. check the scan tool connection to the VCM . refer to «MODULE COMMUNICATIONS NETWORK»(ref-364058) , No Power To The Scan Tool, to diagnose no power to the scan tool.
12. If the scan tool does not communicate with the vehicle: verify the ignition key is in the ON position. verify the scan tool operation with a known good vehicle. refer to «MODULE COMMUNICATIONS NETWORK»(ref-364058) to diagnose no response from the PCM.
13. Carry out the network test. If the scan tool responds with no communication for one or more modules, refer to «MODULE COMMUNICATIONS NETWORK»(ref-364058) . If the network test passes, retrieve and record Continuous Memory Diagnostic Trouble Codes (CMDTCs).
14. Clear the CMDTCs and carry out the self-test diagnostics for the PCM.
15. If the DTCs recovered are related to the concern, go to the «PCM DTC CHART»(ref-364096-S31703869052010062700000) . For all other DTCs, refer to «MULTIFUNCTION ELECTRONIC MODULES»(ref-364059) .
16. If no DTCs related to the concern are retrieved, GO to «SYMPTOM CHART»(ref-364096-S28840366512010062700000) .

DTC Chart

PCM DTC CHART

Symptom Chart

SYMPTOM CHART

PINPOINT TEST A: LOSS OF COOLANT

1. A1 CARRY OUT INSPECTION AND VERIFICATION Carry out the inspection and verification procedure. Were any concerns found? Yes: REPAIR as needed. TEST the system for normal operation. No: GO to A2 .
2. A2 CHECK THE ENGINE COOLANT LEVEL NOTE: Allow the engine to cool before checking the engine coolant level. Ignition OFF. Visually inspect the engine coolant level at the coolant expansion tank. Is the engine coolant level within specifications? Yes: GO to A3 . No: ADJUST the engine coolant level as necessary. GO to A3 .
3. A3 PRESSURE TEST THE ENGINE COOLING SYSTEM Pressure test the engine cooling system. Refer to «COMPONENT TESTS, COOLING SYSTEM PRESSURE TEST»(ref-364096-S12813505132010062700000) . Does the engine cooling system leak? Yes: REPAIR or INSTALL new components. TEST the system for normal operation. No: GO to A4 .
4. A4 CHECK THE ENGINE COOLANT FOR AN INTERNAL LEAK Inspect the engine coolant in the coolant expansion tank and the radiator for signs of engine oil or transmission fluid. Is engine oil or transmission fluid evident in the coolant? Yes: If engine oil is evident, GO to «ENGINE SYSTEM - GENERAL INFORMATION»(ref-364043) for engine diagnosis. If transmission fluid is evident, INSTALL a new radiator. REPAIR the transmission as necessary. Refer to the «AUTOMATIC TRANSAXLE/TRANSMISSION - 4F27E»(ref-361704) for the procedure. TEST the system for normal operation. No: GO to A5 .
5. A5 CHECK THE ENGINE OIL AND TRANSMISSION FLUID FOR COOLANT Remove the oil level indicators from the engine and the transmission. Is coolant evident in the oil or transmission fluid? Yes: If coolant is in the engine oil, GO to «ENGINE SYSTEM - GENERAL INFORMATION»(ref-364043) . If coolant is in the transmission fluid, INSTALL a new radiator. REPAIR the transmission as necessary. Refer to the «AUTOMATIC TRANSAXLE/TRANSMISSION - 4F27E»(ref-361704) for the procedure. No: GO to A6 .
6. A6 CHECK THE COOLING SYSTEM FOR COMBUSTION GASES NOTE: Use U-View® Combustion Leak Tester part number 560000 or equivalent. Using a cooling system combustion gas leak tester, following the instructions supplied with the tester, check the coolant for combustion gases. Are combustion gases present? Yes: GO to «ENGINE SYSTEM - GENERAL INFORMATION»(ref-364043) for engine diagnosis. No: The cooling system is operational.

PINPOINT TEST B: THE ENGINE OVERHEATS

1. B1 CARRY OUT INSPECTION AND VERIFICATION Carry out the inspection and verification procedure. Were any concerns found? Yes: REPAIR as needed. TEST the system for normal operation. No: GO to B2 .
2. B2 CHECK FOR DTCs NOTE: Refer to the «INTRODUCTION - GASOLINE MODELS»(ref-355661) for correct scan tool hook-up procedure. Check for DTC P0217, P1285 or P1299. Is DTC P0217, P1285 or P1299 present? Yes: GO to B3 . No: Actual engine overheating has not been verified. CHECK the engine coolant temperature gauge operation. REFER to «INSTRUMENTATION, MESSAGE CENTER, AND WARNING CHIMES»(ref-364063) . If any other DTCs are retrieved, REFER to the «INTRODUCTION - GASOLINE MODELS»(ref-355661) .
3. B3 CHECK FOR AN AIRFLOW OBSTRUCTION Check the radiator or A/C condenser for an obstruction such as leaves or cardboard. Is an obstruction present? Yes: REMOVE the obstruction. TEST the system for normal operation. No: GO to B4 .
4. B4 CHECK THE ENGINE COOLANT LEVEL NOTE: Allow the engine to cool before checking the coolant level. Ignition OFF. Visually check the engine coolant level in the coolant expansion tank. Is the engine coolant level within specification? Yes: GO to B5 . No: ADJUST the engine coolant level as necessary. GO to B5 .
5. B5 PRESSURE TEST THE ENGINE COOLING SYSTEM Pressure test the engine cooling system. Refer to «COMPONENT TESTS, COOLING SYSTEM PRESSURE TEST»(ref-364096-S12813505132010062700000) . Does the engine cooling system leak? Yes: REPAIR or INSTALL new components. TEST the system for normal operation. No: GO to B6 .
6. B6 CHECK THE PRESSURE RELIEF CAP Carry out the Pressure Relief Cap Pressure Test. Refer to «COMPONENT TEST, PRESSURE RELIEF CAP PRESSURE TEST»(ref-364096-S16015064122010062700000) . Is the pressure relief cap OK? Yes: GO to B7 . No: INSTALL a new pressure relief cap. TEST the system for normal operation.
7. B7 CHECK THE ENGINE COOLANT FOR AN INTERNAL LEAK Inspect the engine coolant in the coolant expansion tank and the radiator for signs of engine oil or transmission fluid. Is engine oil or transmission fluid evident in the coolant? Yes: If engine oil is evident, GO to «ENGINE SYSTEM - GENERAL INFORMATION»(ref-364043) for engine diagnosis. If transmission fluid is evident, INSTALL a new radiator. REPAIR the transmission as necessary. Refer to the «AUTOMATIC TRANSAXLE/TRANSMISSION - 4F27E»(ref-361704) for the procedure. TEST the system for normal operation. No: GO to B8 .
8. B8 CHECK THE ENGINE OIL AND TRANSMISSION FLUID FOR COOLANT Remove the oil level indicators from the engine and the transmission. Is coolant evident in the oil or transmission fluid? Yes: If coolant is in the engine oil, GO to «ENGINE SYSTEM - GENERAL INFORMATION»(ref-364043) . If coolant is in the transmission fluid, INSTALL a new radiator. REPAIR the transmission as necessary. Refer to the «AUTOMATIC TRANSAXLE/TRANSMISSION - 4F27E»(ref-361704) for the procedure. No: GO to B9 .
9. B9 CHECK THE COOLING SYSTEM FOR COMBUSTION GASES NOTE: Use U-View® Combustion Leak Tester part number 560000 or equivalent. Using a cooling system combustion gas leak tester, following the instructions supplied with the tester, check the coolant for combustion gases. Are combustion gases present? Yes: GO to «ENGINE SYSTEM - GENERAL INFORMATION»(ref-364043) for engine diagnosis. No: GO to B10 .
10. B10 CHECK COOLANT CONDITION Check the coolant for dirt, rust or contamination and check the coolant concentration. Is the coolant condition OK? Yes: GO to B11 . No: FLUSH the engine cooling system. REFER to «COOLING SYSTEM FLUSHING»(ref-364096-S27411550402010062700000) . TEST the system for normal operation.
11. B11 CHECK THE ELECTRIC COOLING FAN OPERATION Start the engine. Place the climate control function selector in the MAX A/C position and the blower motor switch in the HI position. Did the electric cooling fan operate? Yes: GO to B12 . No: DIAGNOSE the electric cooling fan operation. REFER to the «INTRODUCTION - GASOLINE MODELS»(ref-355661) .
12. B12 CHECK THE COOLANT PUMP OPERATION Start the engine. Allow the engine to run for 10 minutes. Place the climate control function selector in the MAX HEAT position. Feel the heater outlet hose. Is the heater outlet hose hot? Yes: GO to B13 . No: INSTALL a new coolant pump. TEST the system for normal operation.
13. B13 CHECK THE THERMOSTAT OPERATION Start the engine. Allow the engine to run for 10 minutes. Feel the upper radiator hose. Is the upper radiator hose hot? Yes: CHECK the engine coolant temperature gauge operation. REFER to «INSTRUMENTATION, MESSAGE CENTER, AND WARNING CHIMES»(ref-364063) . No: GO to B14 .
14. B14 VISUALLY INSPECT THE THERMOSTAT Carry out the Thermostat Visual Inspection in «Component Tests»(ref-364096-S01123145002010062700000) . Is the thermostat damaged? Yes: INSTALL a new thermostat. TEST the system for normal operation. No: INSTALL a new thermostat. TEST the system for normal operation. If the engine still overheats, INSTALL a new radiator. TEST the system for normal operation.

PINPOINT TEST C: THE ENGINE DOES NOT REACH NORMAL OPERATING TEMPERATURE

1. C1 CARRY OUT INSPECTION AND VERIFICATION Carry out the inspection and verification procedure. Were any concerns found? Yes: REPAIR as needed. TEST the system for normal operation. No: GO to C2 .
2. C2 CHECK FOR DTC P0125 or P0128 NOTE: Refer to the «INTRODUCTION - GASOLINE MODELS»(ref-355661) for correct scan tool hook-up procedure. Check for DTC P0125 or P0128. Is DTC P0125 or P0128 present? Yes: GO to C3 . No: The cooling system is operational. If an inoperative engine coolant temperature gauge is suspected, CHECK the engine coolant temperature gauge operation. REFER to «INSTRUMENTATION, MESSAGE CENTER, AND WARNING CHIMES»(ref-364063) . If an inoperative climate control system is suspected, CHECK the climate control system operation. REFER to «CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS»(ref-364046) . If any other DTCs are retrieved, REFER to the «INTRODUCTION - GASOLINE MODELS»(ref-355661) .
3. C3 CHECK THE ELECTRIC COOLING FAN OPERATION Allow the engine to cool. Make sure the A/C switch is OFF. Start the engine. Check the electric cooling fan. Is the electric cooling fan on all the time? Yes: DIAGNOSE the electric cooling fan operation. REFER to the «INTRODUCTION - GASOLINE MODELS»(ref-355661) . No: GO to C4 .
4. C4 CHECK THE COOLANT LEVEL NOTE: Allow the engine to cool before checking the coolant level. Visually check the engine coolant level in the coolant expansion tank. Is the engine coolant level within specification? Yes: INSTALL a new thermostat. TEST the system for normal operation. No: GO to «PINPOINT TEST A»(ref-364096-S20157440282010062700000) to diagnose a coolant leak.

Coolant System Pressure Test

Scheme 1

1. Turn the engine OFF.
2. Remove the pressure relief cap. Fill the radiator with coolant if needed.
3. Fit the Radiator/Heater Core Pressure Tester from the Pressure Test Kit to the radiator fill neck.
4. Slowly depress the plunger of the pressure test pump to the maximum allowed pressure and hold for 2 minutes. If the pressure drops within this time, inspect for leaks and repair as necessary.
5. If no leaks are found and the pressure drops, the leak may be internal to the radiator transmission cooler. Inspect the coolant for transmission fluid and the transmission fluid for coolant. Repair as necessary.
6. If there is no contamination of the coolant or transmission fluid, the leak may be internal to the engine. Inspect the coolant for engine oil and the engine oil for coolant. Refer to «ENGINE SYSTEM - GENERAL INFORMATION»(ref-364043) to diagnose the engine.

Thermostat Visual Inspection

1. Remove the thermostat.
2. Examine the thermostat for signs of damage including: Valve not fully seated (light visible through the valve) Foreign material lodged in the main valve Bent or broken frame or flange Bent or broken spring Bent or broken valve or valve stem Wax leaking from wax reservoir or a bulge in the reservoir Any other damage or distortion
3. If damage is found during the inspection, remove any foreign material or broken pieces and install a new thermostat.
4. If no damage is found during the inspection, continue troubleshooting the system concern. Go to the «SYMPTOM CHART»(ref-364096-S28840366512010062700000) for further instructions.

Radiator Leak Test, Removed From Vehicle

Note. Never leak test an aluminum radiator in the same water that copper/brass radiators are tested in. Flux and caustic cleaners may be present in the cleaning tank and they will damage aluminum radiators.

Note. Always install plugs in the transmission fluid cooler fittings before leak testing or cleaning any radiator.

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

1. Leak test the radiator in clean water with air pressurized to the maximum pressure listed in Specifications.