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Home >> Lincoln >> 2018 >> MKZ Select, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1505 (Engine Cooling - 2.3L ECOBOOST (257KW/350PS) - Mi4) >> Diagnosis And Testing >> Engine Cooling >> Diagnostic Routine(s) >> Pinpoint Test B : The Engine Overheats >> Pinpoint Test B : The Engine Overheats

Pinpoint Test B : The Engine Overheats

WARNING: This page is about a different car, the 2018 Ford Focus. However, it is still accessible from the selected car via links, so may be relevant.

  1. B1 CARRY OUT INSPECTION AND VERIFICATION

    • Carry out the Inspection and Verification procedure.

    Are any concerns present? 

    Yes  REPAIR as needed.
    No  GO to  B2

  2. B2 CHECK FOR PCM (POWERTRAIN CONTROL MODULE) DTCS

    • Ignition ON.

    • Using a scan tool, perform PCM self-test.

    Are DTCs P0217, P1285 and/or P1299 reported? 

    Yes  GO to  B3
    No  If the engine overheating symptoms are present or if coolant is low from an overheat GO to  B3 If actual engine overheating has not been verified CHECK the engine coolant temperature gauge operation. REFER to: Instrumentation, Message Center and Warning Chimes . If any other PCM DTCs are retrieved, REFER to: Electronic Engine Controls .

  3. B3 CHECK FOR AN AIRFLOW OBSTRUCTION AND MISSING AIR DEFLECTORS

    NOTE: Verify no vehicle front end damage is present.

    • Check the radiator or A/C condenser for an external obstruction such as leaves or cardboard and verify all air deflectors are present.

    Is an airflow obstruction present or air deflectors missing? 

    Yes  REPAIR as necessary.
    No  GO to  B4

  4. B4 CHECK THE CHT (CYLINDER HEAD TEMPERATURE) AND AMBIENT AIR TEMPERATURE CORRELATION

    • Check temperature values while engine is at ambient temperature, cold soak the engine for a minimum of 6 hours if necessary. Make sure the vehicle has not been in direct sunlight.

    • Using a diagnostic scan tool, monitor the PCM CHT (TEMP) and AAT (TEMP) PIDs.

    Are the temperature readings within 10 degrees of each other? 

    Yes  GO to  B5
    No  INSTALL a new CHT sensor, REFER to: Cylinder Head Temperature (CHT) Sensor .

  5. B5 CHECK THE ENGINE COOLANT LEVEL AND PRESSURE TEST THE COOLING SYSTEM

    • Ignition OFF.

    • Visually check the engine coolant level in the coolant expansion tank and adjust as necessary. Pressure test the cooling system.

    Does the engine cooling system leak externally? 

    Yes  REPAIR or INSTALL new components.
    No  GO to  B6

  6. B6 CHECK THE ENGINE COOLANT FOR AN INTERNAL LEAK

    • Inspect the engine coolant in the coolant expansion tank for signs of engine oil.

    Is engine oil evident in the coolant? 

    Yes  REFER to: Engine .
    No  GO to  B7

  7. B7 CHECK THE ENGINE OIL FOR COOLANT

    • Remove the oil level indicator from the engine.

    Is coolant evident in the oil? 

    Yes  REFER to: Engine .
    No  GO to  B8

  8. B8 CHECK THE COOLING SYSTEM FOR COMBUSTION GASES

    NOTE: Use UView® Combustion Leak Tester part number UVU560000-R 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  REFER to: Engine .
    No  GO to  B9

  9. 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.

  10. 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 the ENGINE CONTROLS - SYMPTOM CHARTS (EXCEPT DIESEL & HYBRID) .

  11. 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. REFER to: Coolant Pump  .

  12. B12 CHECK THE THERMOSTAT 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 lower radiator hose.

    Is the lower radiator hose hot? 

    Yes  CHECK the temperature gauge operation. REFER to: Instrumentation, Message Center and Warning Chimes .
    No  GO to  B13

  13. B13 VISUALLY INSPECT THE THERMOSTAT

    Is the thermostat damaged? 

    Yes  INSTALL a new thermostat. REFER to: Thermostat  .
    No  INSTALL a new thermostat. REFER to: Thermostat  . If the engine still overheats, INSTALL a new radiator. REFER to: Radiator  .
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