Oil Consumption Test

The following diagnostic procedure is used to determine the source of excessive oil consumption.

NOTE: Oil use is normally greater during the first 16,100 km (10,000 miles) of service. As mileage increases, oil use decreases. Vehicles in normal service should get at least 1,450 km (900 miles) per liter after 16,100 km (10,000 miles) of service. High speed driving, towing, high ambient temperature and other factors may result in greater oil use.

1. Define excessive consumption, such as the number of miles driven per liter of oil used. Also determine customer's driving habits, such as sustained high speed operation, towing, extended idle and other considerations.
2. Verify that the engine has no external oil leaks as described under Engine Oil Leaks.
3. Verify that the engine has the correct oil level.
4. Verify that the engine is not being run in an overfilled condition. Check the oil level at least five minutes after a hot shutdown with the vehicle parked on a level surface. In no case should the level be above the top of the cross-hatched area and the letter "F" in FULL. If significantly overfilled, carry out the following step, substep 1 to 4.
5. Carry out an oil consumption test:
6. Check the Positive Crankcase Ventilation (PCV) system. Make sure the system is not plugged.
7. Check for plugged oil drain-back holes in the cylinder head and cylinder block.
8. If the condition still exists after carrying out the above tests go to the next step.
9. Carry out a cylinder compression test. This can help determine the source of oil consumption such as valves, piston rings or other areas.
10. Check valve guides for excessive guide clearance. Install all valve stem oil seals new after verifying valve guide clearance.
11. Worn or damaged internal engine components can cause excessive oil consumption. Small deposits of oil on the tips of the spark plugs can be a clue to internal oil consumption. If internal oil consumption still persists, proceed as follows.
12. Carry out oil consumption test as described to confirm oil consumption concern has been resolved.