GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

Low oil pressure

  1. Verify proper oil level.
  2. Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing .
  3. Repair or replace damaged components, as required.

Worn accessory drive components

Abnormalities, such as severe cracking, bumps, or missing areas in the accessory drive belt and/or misalignment of system components.

  1. Inspect the accessory drive system.
  2. Repair or replace, as required.

Loose or damaged crankshaft balancer

  1. Inspect the crankshaft balancer.
  2. Repair or replace, as required.

Detonation or spark knock

Verify the correct operation of the ignition controls system. Refer to Detonation/Spark Knock .

Loose torque converter bolts - automatic transmission only

  1. Inspect the torque converter bolts and flywheel.
  2. Repair or replace, as required.

Loose or damaged flywheel

Repair or replace the flywheel.

Damaged oil pan contacting the oil pump screen

An oil pan that has been damaged may improperly position the oil pump screen, preventing proper oil flow to the oil pump.

  1. Inspect the oil pan.
  2. Inspect the oil pump screen.
  3. Repair or replace, as required.

Oil pump screen loose, damaged, or restricted

  1. Inspect the oil pump screen.
  2. Repair or replace, as required.

Excessive piston-to-cylinder bore clearance

  1. Inspect the piston and cylinder bore.
  2. Repair, as required.

Excessive piston pin-to-bore clearance

  1. Inspect the piston, piston pin, and connecting rod.
  2. Repair or replace, as required.

Excessive connecting rod bearing clearance

  1. Inspect the following components:
  2. • The connecting rod bearings
    • The connecting rods
    • The crankshaft
    • The crankshaft journals
  3. Repair, as required.

Excessive crankshaft bearing clearance

  1. Inspect the crankshaft bearings and crankshaft journals.
  2. Repair, as required.

Incorrect piston, piston pin, and connecting rod installation

Pistons must be installed with the mark, or dimple, on the top of the piston facing the front of the engine. Piston pins must be centered in the connecting rod pin bore.

  1. Verify the pistons, piston pins, and connecting rods are installed correctly.
  2. Repair, as required.