Oil Pressure Diagnosis and Testing
Tools Required:
  • J 21867 Pressure Gauge
  • J-21867-6 Oil Pressure Adapter Fitting
  1. With the vehicle on a level surface, run the vehicle for a few minutes, allow adequate drain down time, 2–3 minutes, and measure for a low oil level.
  2. If required, add the recommended grade engine oil and fill the crankcase until the oil level measures full on the oil level indicator.
  3. Run the engine briefly, 10–15 seconds, and verify low or no oil pressure on the vehicle gauge or light.
  4. Listen for a noisy valve train or a knocking noise.
  5. Inspect for the following:
    • Foamy oil
    • Slow idle speed
    • Plugged oil filter
    • Oil diluted by the following:
      • Water
      • Engine coolant
      • Unburned fuel mixtures
    • Malfunctioning oil filter bypass valve
    • Incorrect or faulty oil pressure gauge
    • Incorrect or faulty oil pressure gauge sensor
    • Improper engine oil viscosity for the expected temperature

    Object ID: 945276
  6. Disconnect the oil pressure sensor wiring harness.

    7. Object ID: 945280
  7. Remove the oil pressure sensor.
  8. Install the J 21867 Pressure Gauge with the J-21867-6 Oil Pressure Adapter Fitting.
  9. Measure the engine oil pressure.
  10. Compare the readings to the Engine Mechanical Specifications.
  11. If the engine oil pressure is below specifications, inspect the engine for one or more of the following:
    • Loose oil filter adapter bolts
    • Missing or damaged oil filter adapter O-ring seal or seals
    • Worn or dirty oil pump
    • Loose oil pump-to-engine block bolts
    • Loose, plugged or damaged oil pump screen
    • Missing or damaged oil pump screen O-ring seal
    • Damage or leak in the oil pump screen suction tube
    • Malfunctioning oil pump pressure regulator valve
    • Missing or incorrectly installed oil gallery plugs
    • Loose camshaft intermediate drive shaft bolts
    • Excessive bearing clearance for the following:
      • Connecting rod or rods
      • Crankshaft
      • Camshaft or camshafts
      • Camshaft intermediate drive shaft sprocket
    • Cracked, porous or restricted oil galleries
    • Broken valve lifters
  12. Repair or replace components as necessary.