15. Oil Aeration Test
15. OIL AERATION TESTPurpose:
The purpose of this test is to determine if the engine lube oil is aerated and causing poor idle quality.
Oil Aeration Test
- Run engine at 3,000 RPM for 1 minute.
- Take an oil sample from the engine oil temperature (EOT) sensor port at idle.
- Inspect the sample for presence of air bubbles.
- Excessive oil aeration can be caused by depleted oil additives, pick-up tube leak, front cover seal leak, or upper pan seal leak.
Recommended Procedure:
NOTE: The engine must be at operating temperature.
1. Remove the EOT sensor.
2. Install the High Pressure Pump Test Adapter 303-765 or equivalent and Gauge 0-1.1 MPa (0-160 psi) Bar 014-00761 or equivalent.
3. Increase the engine speed to 3,000 RPM and maintain for 1 minute.
4. Return the engine speed to idle.
5. Obtain an oil sample with the engine at idle.
Possible Causes:
- Extended oil drain intervals - the anti-foam additives in the oil may be depleted from severe use or extended intervals
- Air may be present due to recent engine repair on injection control pressure system. It may be necessary to operate the vehicle aggressively for 24-32 km (15-20 miles) to remove excess air
- Incorrect type or grade of oil
Tools Required:
- Clear container - approximately 0.95 L (1 quart)
- Gauge 0-1.1 MPa (0-160 psi) Bar 014-00761 or equivalent
- High Pressure Pump Test Adapter 303-765 or equivalent