2003 GMC Sonoma Owner's Manual - Page 278

Engine Oil Checking Engine Oil It's a good idea to check p u r 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 on the 'VORTEC" 4300 V6 engine is a yellow ring. See Engine Compartment Overviewon page 5-12 for more information on location. 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 actuai 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. 5-15