GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2009 🢒 CTS 🢒 Engine 🢒 Engine Mechanical - 2.8L, 3.0L, 3.2L, or 3.6L 🢒 Lower Engine Noise, Regardless of Engine Speed

Cause

Correction

Low oil pressure
  1. Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing .
  2. 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 Symptoms - Engine Controls .

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

Loose or damaged engine flywheel

Repair or replace the engine 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 the connecting rod.
  2. Repair or replace as required.

Excessive connecting rod bearing clearance

Inspect the following components, and repair as required:

    • The connecting rod bearings
    • The connecting rods
    • The crankshaft
    • The crankshaft journals

Excessive crankshaft bearing clearance

Inspect the following components, and repair as required:

    • The crankshaft bearings
    • The crankshaft journals
    • 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.