Component Tests and General Diagnostics

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 GM P/N 12345610 or equivalent, 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 oil indicator light.
Listen for a noisy valve train or 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 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