GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

Important: A cold piston knock which disappears in 1.5 minutes should be considered acceptable. A cold engine knock usually disappears when the specific cylinder secondary ignition circuit is grounded out during diagnosis.

DEFINITION: A light rattle/tapping noise may indicate a valve train, upper engine concern, or a low rumble/knocking may indicate a crankshaft or piston, lower engine concern.

Incorrect oil filter without anti-drainback feature

Install the correct oil filter.

Incorrect oil viscosity

  1. Drain the oil.
  2. Install the correct viscosity oil.

High valve lifter leak down rate

Replace the lifters as required.

Worn crankshaft thrust bearing

    • Inspect the thrust bearing and crankshaft.
    • Repair or replace as required.

Damaged or faulty oil filter by-pass valve

    • Inspect the oil filter by-pass valve for proper operation.
    • Repair or replace as required.