Oil Pressure Diagnosis and Testing
Tools Required
J-21867-850 Oil Pressure Gage Adapter. See Special Tools .
- With the vehicle on a level surface, allow adequate drain down time of 2-3 minutes and measure for a low oil level.
Add the recommended grade engine oil and fill the crankcase until the oil level measures full on the oil level indicator.
- Run the engine, and verify low, or no oil pressure on the vehicle gauge or light.
Listen for a noisy valve train or a knocking noise.
- Inspect for the following:
- Correct oil filter with anti-drain back feature and O-ring on the cylinder block side of the filter
- Oil diluted by moisture or unburned fuel mixtures
- Improper oil viscosity for the expected temperature
- Incorrect or malfunctioning oil pressure sender
- Incorrect or malfunctioning oil pressure gauge
- Plugged oil filter
- Malfunctioning oil bypass valve
- Remove the oil pressure sender or another engine block oil gallery plug.
- Install J-21867-850 and an oil pressure gauge and measure the engine oil pressure. See Special Tools .
- Compare the readings to specifications. Refer to Engine Mechanical Specifications (LAP, LE8) or Engine Mechanical Specifications (LAT, LE5, LE9) .
- If the engine oil pressure is below specifications, inspect the engine for one or more of the following:
- Correct oil filter with anti-drain back feature and O-ring on the cylinder block side of the filter
- Oil pump worn or dirty
Refer to Oil Pump Disassemble .
- Oil pump-to-engine front cover bolts loose
Refer to Engine Front Cover and Oil Pump Installation .
- Oil pump screen loose, plugged, or damaged
- Oil pump screen O-ring seal missing or damaged
- Malfunctioning oil pump pressure regulator valve
- Excessive bearing clearance
- Cracked, porous or restricted oil galleries
- Oil gallery plugs missing or incorrectly installed
Refer to Engine Block Assemble .
- Broken lash adjusters