GM Service Manual Online
For 1990-2009 cars only

Checking Engine Oil

It is a good idea to check the engine oil level at each fuel fill. In order to get an accurate reading, the oil must be warm and the vehicle must be on level ground.

The engine oil dipstick handle is a yellow loop. See Engine Compartment Overview for the location of the engine oil dipstick.

  1. Turn off the engine and give the oil several minutes to drain back into the oil pan. If this is not done, the oil dipstick might not show the actual level.
  2. Pull out the dipstick and clean it with a paper towel or cloth, then push it back in all the way. Remove it again, keeping the tip down, and check the level.

When to Add Engine Oil

L6 Engine


Object Number: 1226505  Size: B1

V8 Engine


Object Number: 877099  Size: B1

If the oil is below the L mark for the L6 engine or the cross-hatched area at the tip of the dipstick for the V8 engine, add at least one quart/liter of the recommended oil. This section explains what kind of oil to use. For engine oil crankcase capacity, see Capacities and Specifications.

Notice: Do not add too much oil. If the engine has so much oil that the oil level gets above the cross-hatched area (F) that shows the proper operating range for the L6 engine or above the cross-hatched area for the V8 engine, the engine could be damaged.

Except 6.0L V8 (VIN Code H) Engine


Object Number: 824596  Size: A2

6.0L V8 (VIN Code H) Engine


Object Number: 1391076  Size: A2

See Engine Compartment Overview for the location of the engine oil fill cap.

Add enough oil to put the level somewhere in the proper operating range. Push the dipstick all the way back in when through.

6.0L V8 (VIN Code H) Engine Only

Remove the engine cover to access the engine oil fill cap:

  1. Remove the screw in the center of the cover.
  2. Remove the cover from the stud on the driver side.
  3. Pull the cover up and off the bracket.
  4. Reverse the steps to reinstall.

What Kind of Engine Oil to Use

Except Vehicles with 6.0L V8 (VIN Code H) Engine

Look for three things:


Object Number: 1501606  Size: B4
    • GM6094M
        Use only an oil that meets GM Standard GM6094M.
    • SAE 5W-30
        SAE 5W-30 is best for the vehicle. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils such as SAE 20W-50.
    • American Petroleum Institute (API) starburst symbol

Object Number: 808500  Size: A2

Oils meeting these requirements should have the starburst symbol on the container. This symbol indicates that the oil has been certified by the American Petroleum Institute (API).

Notice: Use only engine oil identified as meeting GM Standard GM6094M and showing the American Petroleum Institute Certified For Gasoline Engines starburst symbol. Failure to use the recommended oil can result in engine damage not covered by the vehicle warranty.

For 6.0L V8 (VIN Code H) Engine Vehicles Only

Look for three things:


Object Number: 1506636  Size: B4
    • GM4718M
        This vehicle's engine requires a special oil meeting GM Standard GM4718M. Oils meeting this standard may be identified as synthetic. However, not all synthetic oils will meet this GM standard. Use only an oil that meets GM Standard GM4718M.

       Notice: Using oils that do not have the GM4718M Standard designation can cause engine damage not covered by the vehicle warranty.

    • SAE 5W-30
        SAE 5W-30 is best for the vehicle. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils such as SAE 20W-50.
    • American Petroleum Institute (API) starburst symbol

Object Number: 808500  Size: A2

Oils meeting these requirements should have the starburst symbol on the container. This symbol indicates that the oil has been certified by the American Petroleum Institute (API).

This vehicle's engine was filled at the factory with a Mobil 1® synthetic oil meeting all requirements for this vehicle.

Substitute Engine Oil: When adding oil to maintain engine oil level, oil meeting GM Standard GM4718M might not be available. You can add substitute oil designated SAE 5W-30 with the starburst symbol at all temperatures. Substitute oil not meeting GM Standard GM4718M should not be used for an oil change.

Cold Temperature Operation

Except Vehicles with 6.0L V8 (VIN Code H) Engine

If in an area of extreme cold, where the temperature falls below -20°F (-29°C), use either an SAE 5W-30 synthetic oil or an SAE 0W-30 engine oil. Both provide easier cold starting for the engine at extremely low temperatures. Always use an oil that meets the required specification, GM6094M. See "What Kind of Engine Oil to Use" for more information.

Engine Oil Additives / Engine Oil Flushes

Do not add anything to the oil. The recommended oils with the starburst symbol that meet GM standards are all that is needed for good performance and engine protection.

Engine oil system flushes are not recommended and could cause engine damage not covered by the vehicle warranty.