GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2002 🢒 Tracker - 2WD 🢒 Engine 🢒 Engine Mechanical - 2.5L (LE8) 🢒 Oil Pressure Diagnosis and Testing

Oil Pressure Test
  1. Remove the exhaust manifold heat shield.

    2. Object Number: 644070 Size: SH
  2. Remove the oil pressure switch from the engine block.
  3. Install a pressure gauge in place of the oil pressure switch.
  4. Start the engine and run at idle until normal operating temperature is reached.
  5. Raise the engine speed to 4000 RPM and measure the oil pressure.

    6. Normal Oil Pressure
    390-470 kPa (56-67 psi) at 4000 RPM

  6. If the oil pressure is below specification refer to the following table.
  7. Stop the engine.
  8. Remove the pressure gauge.

    9. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  9. Install the oil pressure switch.

    10. Tighten
    Tighten the oil pressure switch to 14 N·m (11 lb ft).

  10. Install the exhaust manifold heat shield.
  11. Run the engine and inspect for oil leaks from the oil pressure switch.

Oil Pressure Diagnosis

Problem

Action

The oil level is low.

Fill the oil to the FULL mark on the oil level indicator.

The idle speed is slow.

Adjust the idle speed. Refer to Minimum Idle Speed Inspection/Adjustment in Engine Controls-2.5L.

The oil pressure switch is incorrect or malfunctioning.

Replace the oil pressure switch.

The oil pressure indicator is incorrect or malfunctioning.

Replace the oil pressure indicator.

The oil viscosity is improper.

Fill the oil tank. Use oil of the proper viscosity for the expected temperature.

The oil is diluted with one of the following materials:

    • Moisture
    • An unburned fuel mixture

Fill with new oil. Investigate the cause of the oil dilution. Inspect the following:

    • The PCV system
    • The ignition system
    • The fuel system
    • The engine mechanical condition

The oil pump is worn or dirty.

Replace or clean the oil pump as necessary.

The oil filter is plugged.

Replace the oil filter.

The oil pickup screen is loose or plugged.

Adjust or replace the screen as necessary.

The oil pickup tube has a hole.

Replace the tube.

The oil pickup tube O-ring is damaged.

Replace the O-ring.

The bearing clearance is excessive.

Replace the connecting rod or the main bearings as necessary.

The oil galleries display one of the following conditions:

    • Cracked
    • Porous
    • Restricted

Repair or replace the block as necessary.

The gallery plugs are missing or incorrectly installed.

Install the plugs or repair as necessary.

The oil pump pressure regulator valve is malfunctioning.

Replace the valve.

The camshaft is worn or poorly machined.

Replace the camshaft or the cylinder head and bearing caps.

The valve guides are worn.

Replace the guides.

Oil pump malfunction.

The oil pump is driven by a chain from the crankshaft. Inspect for a stretched or damaged chain and for correct pump output.