Pinpoint Test B: The Engine Overheats
WARNING: This page is about a different car, the 2010 Mercury Milan and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
Always allow the engine to cool before opening the cooling system. Do not unscrew the coolant pressure relief cap when the engine is operating or the cooling system is hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. Failure to follow these instructions may result in serious personal injury.
- B1 CARRY OUT INSPECTION AND VERIFICATION
- Carry out Inspection and Verification procedure.
- Were any concerns found?
- Yes: REPAIR as needed. TEST the system for normal operation.
- No: GO to B2.
- B2 CHECK FOR DTCs
- Check for DTC P0217, P1285 or P1299.
- Is DTC P0217, P1285 or P1299 present? NOTE: Refer to INTRODUCTION -- HYBRID for correct scan tool hook-up procedure.
- Yes: GO to B3.
- No: Actual engine overheating has not been verified. CHECK the Engine Coolant Temperature (ECT) gauge operation. REFER to INSTRUMENTATION, MESSAGE CENTER AND WARNING CHIMES . If any other DTCs are retrieved, REFER to INTRODUCTION -- HYBRID .
- B3 CHECK FOR AN AIRFLOW OBSTRUCTION
- Check the radiator or A/C condenser for an external obstruction such as leaves or cardboard.
- Is an obstruction present?
- Yes: REMOVE the obstruction. TEST the system for normal operation.
- No: GO to B4.
- 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 degas bottle.
- Is the engine coolant level within specification?
- B5 PRESSURE TEST THE ENGINE COOLING SYSTEM
- Pressure test the engine cooling system. Refer to COOLING SYSTEM PRESSURE TEST .
- Does the engine cooling system leak?
- Yes: REPAIR or INSTALL new components. TEST the system for normal operation.
- No: GO to B6.
- B6 CHECK THE ENGINE COOLANT FOR AN INTERNAL LEAK
- Inspect the engine coolant in the degas bottle for signs of engine oil.
- Is engine oil evident in the coolant?
- B7 CHECK THE ENGINE OIL FOR COOLANT
- Remove the oil level indicator from the engine.
- Is coolant evident in the oil?
- B8 CHECK THE COOLING SYSTEM FOR COMBUSTION GASES
- Using a cooling system combustion gas leak tester, following the instructions supplied with the tester, check the coolant for combustion gases.NOTE: Use U-View® Combustion Leak Tester, part No. 560000 or equivalent.
- Are combustion gases present?
- Using a cooling system combustion gas leak tester, following the instructions supplied with the tester, check the coolant for combustion gases.
- B9 CHECK COOLANT CONDITION
- Check the coolant for dirt, rust or contamination and check the coolant concentration.
- Is the coolant condition OK?
- Yes: GO to B10.
- No: FLUSH the engine cooling system. REFER to COOLING SYSTEM FLUSHING . TEST the system for normal operation.
- B10 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 B11.
- No: DIAGNOSE the electric cooling fan operation. REFER to INTRODUCTION -- HYBRID .
- B11 CHECK THE COOLANT PUMP OPERATION
- Start the engine.
- Allow the engine to run for 30 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 B12.
- No: INSTALL a new coolant pump. TEST the system for normal operation.
- B12 CHECK THE THERMOSTAT OPERATION
- Start the engine.
- Allow the engine to run for 30 minutes. Feel the lower radiator hose.
- Is the lower radiator hose hot?
- Yes: CHECK the engine coolant temperature gauge operation. REFER to INSTRUMENTATION, MESSAGE CENTER AND WARNING CHIMES .
- No: GO to B13.
- B13 VISUALLY INSPECT THE THERMOSTAT
- Carry out Thermostat Visual Inspection .
- 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.