- With the vehicle on a level surface, allow adequate drain down time, 2-3 minutes, and measure for the proper engine oil level. An overfull oil level causes aeration within the oil.
- Add the recommended grade engine oil GM P/N 12345610, (Canadian P/N 993193), or equivalent, and fill the crankcase until the oil level measures FULL on the oil level indicator.
- Operate the engine and verify low or no oil pressure on the vehicle oil pressure gage or oil indicator lamp.
Listen for a noisy valve train or knocking noise.
- Inspect for the following conditions:
| • | Engine oil diluted by moisture or unburned fuel mixtures |
| • | Improper engine oil viscosity for the expected temperature |
| • | Incorrect or faulty oil pressure gage sensor |
| • | Incorrect or faulty oil pressure gage |
| • | Malfunctioning oil filter bypass valve |
- Remove the oil pressure gage sensor or another engine block oil gallery plug.
- Install an oil pressure gage and measure the engine oil pressure.
- If the engine oil pressure is below specifications, inspect the engine for 1 or more of the following conditions:
| • | Malfunctioning oil pump pressure relief valve |
| • | Oil pump screen loose, plugged, or damaged |
| • | Excessive bearing clearance or worn bearings |
| • | Cracked, porous, or restricted oil galleries |
| • | Engine block oil gallery plugs missing or incorrectly installed |
