GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

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

  1. Check the crankshaft end play.
  2. Inspect the thrust bearing and crankshaft.
  3. Repair or replace as required.

Faulty oil filter bypass valve.

The valve is now internal to the oil filter.

Replace the oil filter as required.