Oil Consumption Diagnosis

Excessive oil consumption, not due to leaks, is the use of more than 0.95 liter (1 quart) of engine oil within 379 liters (100 gallons) of fuel used. However, during initial engine break-in periods 5 000-6 500 kilometers (3,000-4,000 miles) oil consumption may exceed 1.9 liters (2 quarts) or more per 379 liters (100 gallons) of fuel used. The causes of excessive oil consumption include the following conditions:

• External oil leaks. Tighten bolts and/or replace gaskets and oil seals as necessary.
• Incorrect oil level or improper reading of oil level indicator. With the vehicle on a level surface, allow adequate drain down time and check for the correct oil level.
• Improper oil viscosity. Use recommended SAE viscosity for the prevailing temperatures.
• Continuous high speed driving and/or severe usage.
• Crankcase ventilation system restrictions or malfunctioning components.
• Valve guides and/or valve stem oil seals worn, or the seal omitted. Ream guides and install oversize service valves and/or new valve stem oil seals.
• Piston rings broken, improperly installed, worn, or not seated properly. Allow adequate time for rings to seat. Replace broken or worn rings as necessary.
• Piston improperly installed or piston size is incorrectly selected.