GM Service Manual Online
For 1990-2009 cars only

Refer to Engine Mechanical Specifications for oil pressure specifications.

Problem

Action

The oil level is low.

Fill the oil to the FULL mark on the oil level indicator.

The idle speed is slow.

Adjust the idle speed.

The oil pressure switch is incorrect or malfunctioning.

Replace the oil pressure switch.

The oil pressure indicator is incorrect or malfunctioning.

Replace the oil pressure indicator.

The oil viscosity is improper.

Fill the oil tank. Use oil of the proper viscosity for the expected temperature.

The oil is diluted with one of the following materials:

    • Moisture
    • An unburned fuel mixture

Fill with new oil.

The oil pump is worn or dirty.

Replace or clean the oil pump as necessary.

The oil filter is plugged.

Replace the oil filter.

The oil pickup screen is loose or plugged.

Adjust or replace the screen as necessary.

The oil pickup tube has a hole.

Replace the tube.

The bearing clearance is excessive.

Replace the bearings as necessary.

The oil galleries display one of the following conditions:

    • Cracked
    • Porous
    • Restricted

Repair or replace the block as necessary.

The gallery plugs are missing or incorrectly installed.

Install the plugs or repair as necessary.

The oil pump pressure regulator valve is malfunctioning.

Replace the valve.

The camshaft is worn or poorly machined.

Replace the camshaft.

The valve guides are worn.

Replace the guides.