Oil Pressure Diagnosis and Testing

- With the vehicle on a level surface, allow adequate drain down time (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:
- 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 a oil pressure gauge and measure the engine oil pressure.
- Compare the readings to specifications. Refer to Engine Mechanical Specifications.
- If the engine oil pressure is below specifications, inspect the engine for one or more of the following:
- Oil pump worn or dirty.
Refer to Oil Pump Clean And inspect.
- Oil pump-to-engine block bolts loose.
Refer to 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.
Refer to Crankshaft and Bearings Clean and Inspect.
- Cracked, porous or restricted oil galleries
- Oil gallery plugs missing or incorrectly installed.
Refer to Cylinder Block Plug Installation.
- Broken valve lifters