2004 GMC Sierra 1500 Pickup Owner's Manual - Page 418

Engine Oil If your vehicle has a diesel engine, see "Engine Oil" in the Diesel Engine Supplement. If the CHECK OIL LEVEL light appears on the instrument cluster (except vehicles equipped with the 4.3L engine), it means you need to check your engine oil level right away. For more information, see Driver Information Center (DIC) on page 3-55. You should check your engine oil level regularly; this is an added reminder. Turn off the engine and give the oil several minutes to drain back into the oil pan. If you don't, the oil dipstick might not show the actual level. 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. Checking Engine Oil It is a good idea to check your engine oil every time you get fuel. 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 on page 5-12 for the location of the engine oil dipstick. All Other Engines 8.1L Engine 5-18