Engine Lubrication: Testing and Inspection

Oil Consumption Diagnosis

Excessive oil consumption (not due to leaks) is the use of 1.9 liters (2 quarts) of engine oil within 3,200 kilometers (2,000 miles). However, during initial engine break-in periods 4,828 - 6,437 kilometers (3,000 - 4,000 miles) oil consumption may exceed 1.9 liters (2 quarts) or more. The causes of excessive oil consumption include the following conditions:
- External oil leaks. Tighten the 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 the valve 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 the piston rings to seat. Replace broken or worn piston rings as necessary.
- Piston improperly installed or miss4itted.

Oil Pressure Diagnosis and Testing

1. With the vehicle on a level surface, allow adequate drain down time (2 - 3 minutes) and measure for a low engine oil level.
Add the recommended grade engine oil, and fill the crankcase until the oil level measures FULL on the oil level indicator.
2. Operate the engine and verify low or no oil pressure on the vehicle oil pressure gauge or the oil indicator light.
Listen for a noisy valve train or a knocking noise.
3. Inspect for the following:
- Engine oil diluted by moisture or unburned fuel mixtures
- Improper engine oil viscosity for the expected temperature
- Incorrect or faulty oil pressure gauge sensor
- Incorrect or faulty oil pressure gauge
- Plugged oil filter
- Malfunctioning oil filter bypass valve
4. Remove the oil pressure gauge sensor or another engine block oil gallery plug.
5. Install an oil pressure gauge and then measure the engine oil pressure.
6. If the engine oil pressure is below specifications, inspect the engine for one or more of the following:
- Oil pump worn or dirty
- Malfunctioning oil pump pressure relief valve
- Oil pump screen loose, plugged, or damaged
- Excessive bearing clearance
- Cracked, porous or restricted oil galleries
- Engine block oil gallery plugs missing or incorrectly installed
- Broken valve lifters