2888340 - D30 ENGINE OVERHEATING / WITH THE FAN WORKING

The reading on the special instrument in the panel shows a high engine coolant temperatureThe cooling fan comes on normally (Otherwise  See table D31  ENGINE OVERHEATING).
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation

Preliminarily check:

  • engine coolant level
  • radiator cleanliness and condition
  • condition of the expansion tank, and particularly the cap seal
Continue to Step 1Insufficient engine coolant levelTop up the engine coolant level If the defect persists, See table   X10 
Cap faultyReplace the component (see Assembly 1048A)
Air intake circuit component damagedRepair or replace the cap ( Op. 1088A10)
Radiator dirty, damaged or deformedClean the radiator. If necessary, replace it Op. 1088B24
1TEMPERATURE GAUGE OPERATION CHECKAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket (in the engine management control unit ambient): read the engine temperature value shown amongst the parameters and compare it with the instrument readingContinue to Step 2Values do not agree, instrument reading faultySee table   K26 
2CHECK COOLANT TEMPERATURE SENSORAll OKProblems metOperation
1.6 16vCheck that the engine coolant temperature sensor is working: See Test   1056C  Checking engine coolant temperature sensor operation Continue to Step 3Sensor faultyReplace temperature sensor Op.   1056B50 
Connections not correctRestore the connections ( See   E4010  INSTRUMENT PANEL )
1.9 JTD 8VCheck that the engine coolant temperature sensor is working: See Test   1060E  Checking engine coolant temperature sensor operation Continue to Step 3Sensor faultyReplace temperature sensor Op.   1060G14 
Connections not correctRestore the connections ( See   E4010  INSTRUMENT PANEL
3CHECK THERMOSTAT UNITAll OKProblems metOperation

Check

  • the condition of the thermostat unit
  • that it is correctly calibrated
Continue to Step 4Thermostat unit faultyBleed the system, replace the thermostat unit if the anomaly persists Op.   1088C40 
4WATER PUMP CHECKAll OKProblems metOperation

Check

  • the condition of the water pump
  • the seal of the gaskets
Continue to Step 5Water pump faultyReplace the water pump or the gaskets Op.   1088C12 
5CHECKING CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsSearch for the fault starting from another symptom'