1999 Chevrolet Silverado 1500 Pickup Owner's Manual - Page 310

yellowblue Engine Oil (Gasoline Engine) If your vehicle has a diesel engine, see "Engine Oil (Diesel Engine)" in the Diesel Engine Supplement. If the CHECK ENG OIL LEVEL light on the instrument panel comes on, it means you need to check your engine oil level right away. For more information, see "CHECK ENG OIL LEVEL" in the Index. You should check your engine oil level regularly; this is an added reminder. It's 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 has a yellow ring handle and is located on the passenger's side of the engine. 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. 6-12