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

    • Drain the oil.
    • Install the correct viscosity oil.

High valve lifter leak down rate

Replace the lifters as required.

Worn crankshaft thrust bearing

    • Check the crankshaft endplay.
    • 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.