An important fluid to check is engine oil because it cools, cleans, lubricates, and seals the internal engine components.
Engine Oil Types. Clean engine oil is gold in color, while dirty engine oil is black. Common multigrade engine oils are 0W-20, 5W-20, and 5W-30 but always refer to the owner’s manual because there are many different viscosities and brands available. Synthetic and semi-synthetic oils are also available. Some new vehicles come with synthetic oil from the factory.
Checking Engine Oil. To check the engine oil, shut off the engine, apply the parking brake, open the hood, and look for the engine oil dipstick. To get an accurate reading it is best to check the engine oil when the engine is cold. The engine oil dipstick runs through a metal tube that is usually located on the side of the engine on rear-wheel drive vehicles or on the front of the engine on front-wheel drive vehicles. Refer to the owner’s manual if you have questions on the location of the dipstick. Note: Some vehicles do not have an oil dipstick. They use an electronic oil level monitor. Check the owner’s manual.
Reading the Dipstick. Pull out the dipstick, wipe it off with a paper towel, reinsert it completely into the tube, remove again, and note the reading. The engine oil should be in the safe range. Most automotive engines have an oil capacity between four to five quarts (3.8 to 4.7 L). Vehicle manufacturers suggest adding oil when the engine is low one quart (≈1 L).
Adding Engine Oil. To add engine oil, locate the oil filler cap on the engine valve cover. Use a clean funnel to add the correct amount of engine oil. Give the engine oil time to flow to the oil pan. Recheck the level and correct if necessary. Do not overfill.