184000598 - X05 EXCESSIVE OIL CONSUMPTION

The engine is running smoothly, but the oil consumption is higher than previously recorded during the life of the vehicle.
High consumption during the first few thousand kilometres is considered normal.
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation

Check:

  • that the level of the engine oil is not high
  • that there are no local leaks
  • that there is no engine oil in the coolant
  • that the end of the exhaust pipe is not dirty with oil
  • that there are no blueish exhaust fumes
Continue to Step 1Fluid level not correctRestore the correct level
Localised engine oil leaksEliminate localised leak
Oil in the cooling circuitContinue to Step 1
Exhaust tail pipe dirty with oilContinue to Step 2
that there are no blue exhaust fumesContinue to Step 2
1CHECKING CYLINDER HEADAll OKProblems metOperation
Remove the cylinder head.

That that the following are absent:

  • Wear on valve stem with excessive clearance between the valve stem and valve guide and between the valve stem and oil seals
  • Oily deposits on the valves;
  • Defects in the cylinder block/crankcase surface;
  • Defects in the cylinder head gasket;
Continue to Step 2Excessive clearance between the valve stem and valve guide and between the valve stem and oil sealReplace the damaged/worn components
Presence of oily dross on the valvesOverhaul the cylinder head
Cylinder block/crankcase plane defectiveReface the cylinder block/crankcase
Cylinder head gasket faultCheck planarity of Cylinder head/Crankcase mating surfaces and replace the cylinder head gasket
2ENGINE OIL PENETRATION CHECKAll OKProblems metOperation

Check the piston seals, in particular:

  • that they are not broken or damaged
  • that the actual rings are correctly fitted
  • that there is no seizing or sticking in the grooves
Continue to Step 3Piston seals damaged or seizedReplace pistons, pins and seals
Piston seals not correctly fittedFit the seals correctly
3CYLINDER LINER/BORE CHECKAll OKProblems metOperation

Check the cylinder liners/bores. In particular:

  • absence of scoring/vitrification
  • Linear dimensions, particularly the lack of ovality/taper/wear
  • Correct piston - liner installation clearance
Continue to Step 4Liners with scoring and/or vitrificationGrind the cylinder liners/bores
Dimensions out of tolerance: presence of ovality/taper/wearGrind the cylinder liners/bores
Fitting clearance incorrectReplace the pistons, pins and seals, respecting the fitting clearances
4CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosis.