Here are a few pictures that I made for you to give you a basic overview of engine and under car parts and components.
Make sure there is no milky residue under the oil cap or inside of the valve cover.
Black oil is not the best thing either. If the oil is black and sludgy, you’ll want to change it as soon as you can. You’ll notice that the car runs better with a fresh batch of oil.
Plus you can say New Oil in your Ad.
Remember, milky oil means that there is a water leak in the engine, usually caused by a cracked head or a blown head gasket.