2751138 - X10 ENGINE COOLANT LEAKS

A leak of engine coolant is seen with dripping and/or fouling of the engineVersions with and without air conditioning.
Results of the tests
1PRELIMINARY CHECKSAll OKProblems metOperation
Carry out a visual inspect to locate the component or area which is leaking.If the visual inspection is not sufficient, wash the engine, dry it, start it and run it slowly until it comes up to temperature; to identify the leak, carry out a leak test on the system ( Op.   0510C30  )Continue to Step 2Leak from the pipesContinue to Step 3
Leak from the radiatorContinue to Step 5
Leak from the expansion tankContinue to Step 6
Leak from the water pumpContinue to Step 8
Leak from the thermostat unitContinue to Step 7
Leak from the cylinder headContinue to Step 9
Leak from the heater radiatorContinue to Step 4
Seepage of oil or water between the engine and the cooling circuitContinue to Step 2
2PRELIMINARY CHECKSAll OKProblems metOperation

Check, in order, that the following are not present:

  • Engine oil in the coolant.
  • Water or emulsion in the engine oil.
Continue to Step 10Oil in the engine coolant radiatorContinue to Step 9
Emulsion or oil in the expansion tankContinue to Step 9
Emulsion or water in the engine oil sumpContinue to Step 11
3PIPES CHECKAll OKProblems metOperation

Check the condition and seal of the pipes. In particular:

  • condition and correct fitting of the bands
  • condition of hoses, connectors and plugs
End of diagnosisBand tightening not correct.Restore the correct tightening.
Band tightening not correct.Replace the components involved
4HEATER CHECKAll OKProblems metOperation
Check the condition of the heater radiator and relevant hoses and bands.End of diagnosisHeater radiator damaged, blocked, distorted.Replace the radiator.
Hoses and/or bands faultyReplace the components involvedContinue to Step 3
5CHECK ON RADIATORAll OKProblems metOperation
Check the condition of the engine coolant radiator and relevant hoses and bands.End of diagnosisRadiator damaged, blocked, distortedReplace the engine coolant radiator
Radiator damaged, blocked, distortedContinue to Step 3
6CHECK EXPANSION TANKAll OKProblems metOperation

Visually inspect:

  • The condition of the expansion tank;
  • The seal of the plug and breather valve.
End of diagnosisTank damaged or distorted.Replace the reservoir
Tank damaged or distorted.Replace the cap
7THERMOSTAT UNIT CHECKAll OKProblems metOperation

Visually inspect:

  • The condition of the thermostat unit;
  • The seal of the gaskets
End of diagnosisThermostat group faultyReplace the thermostat group
Thermostat group faultyReplace the gaskets.
8CHECK ON WATER PUMPAll OKProblems metOperation

Visually inspect:

  • The condition of the water pump;
  • The seal of the gaskets
End of diagnosisWater pump faulty.Replace the water pump.
Gasket/s damagedReplace the gaskets
9CYLINDER HEAD COMPRESSION CHECKAll OKProblems metOperation
Carry out the cylinder head compression test using the Examiner Op. 0520G15Continue to Step 12Cylinder head compression faultyReplace the gasket and/or retighten correctly
10CHECKING CYLINDER HEAD GASKETAll OKProblems metOperation

Visually inspect:

  • That the cylinder head tightening is correct;
  • The seal of the gasket
Continue to Step 11Cylinder head tightening not correctRestore the correct tightening
Gasket damagedReplace the seal
11CYLINDER BLOCK/CRANKCASE PLANE CHECKAll OKProblems metOperation
Remove the cylinder head.

That that the following are absent:

  • oily dross on the valves;
  • defects in the cylinder block/crankcase plane;
  • defects in the cylinder head gasket;
Continue to Step 12Cylinder block/crankcase plane defectiveReface the cylinder block/crankcase
Presence of oily dross on the valvesOverhaul the cylinder head
12Continue as instructed by the testerAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsContinue to Step 1