Oil Pressure Diagnosis and Testing
WARNING: This page is about a different car, the 2002 GMC Yukon XL, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- With the vehicle on a level surface, allow adequate drain down time, 2-3 minutes, and measure for the proper engine oil level. Too high an oil level will cause 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 light.
Listen for a noisy valve train or knocking noise.
- 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 gage sensor
- Incorrect or faulty oil pressure gage
- Plugged oil filter
- 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 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 or worn bearings
- Cracked, porous or restricted oil galleries
- Engine block oil gallery plugs missing or incorrectly installed
- Broken valve lifters