Oil Pressure Diagnosis and Testing
WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. 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 a low engine oil level.
Add the recommended grade engine oil, 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 the oil indicator light.
Listen for a noisy valve train or a 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.
- Start the engine and then allow the engine to reach normal operation temperature.
- Measure the engine oil pressure at the following RPM:
Specification
- 7.1. 42 kPa (6 psig) minimum, at 1,000 RPM
- 7.2. 125 kPa (18 psig) minimum, at 2,000 RPM
- 7.3. 166 kPa (24 psig) minimum, at 4,000 RPM
- If the engine oil pressure is below minimum 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