312000202 - X005 EXCESSIVE OIL CONSUMPTION

The engine seems to be running smoothly, but the fuel consumption is higher than ever before.
High consumption during the first few thousands of Km of the vehicle''s life is considered normal.
Test results
0PRELIMINARY CHECKSAll OKProblems encounteredOperation
Visually check for any leaks that could have caused the high consumption.Check that there is no engine oil in the coolant, also check that the exhaust tail pipe is not dirty with oil and check that there are no bluish exhaust fumesMove on to Step 11. Obvious oil leaks.2.Engine oil in the cooling circuit.3. Exhaust tail pipe dirty with oil.4. Presence of bluish exhaust fumes.1. Locate and eliminate the oil leaks.2. Move on to Step 1.3. Move on to Step 1.4. Move on to Step 1.
1CYLINDER HEAD OIL PENETRATION CHECKAll OKProblems encounteredOperation
Remove the head and check:

  • no carbon deposits in the combustion chambers and on the inlet valves
  • no wear on the valve stems
Move on to Step 2Excessive clearance between the valve stem and valve guide and between the valve stem and oil sealReplace the damaged/worn components    Op. 1016E10 SINGLE CYLINDER HEAD, REMOVED - OVERHAUL
2ENGINE OIL PENETRATION CHECKAll OKProblems encounteredOperation
Check the piston seals, in particular:

  • that they are not broken or damaged;
  • that the seals are correctly fitted;
  • that there is no seizing in the piston ring grooves.
Move on to Step 31. Piston rings damaged or seized.2. Piston rings not correctly fitted.1. Replace the pistons, gudgeon pins and rings.2. Fit the piston rings correctly.
3CYLINDER BORE CHECKAll OKProblems encounteredOperation
Check:

  • the condition of the surfaces and the dimensions (ovality/taper) of the cylinder bores;
  • piston-bore fitting clearance.
End of diagnosis1. Bore surfaces do not conform.2. Dimensions outside of the tolerance.3. Fitting clearance not correct.1. Regrind the cylinder bores.2. Regrind the cylinder bores.3. Replace the pistons, gudgeon pins and piston rings following the fitting clearances.