Teaching a Child How Engine Oil Works

Looking at Your Car

• Unless you are an auto mechanic, you probably won't have a real car motor that you can show your child. But you can share the location of the oil cap under the hood, how to check the oil, and how to add new oil if it is low. Explain that cars need oil to make all of their parts move correctly. You might even explain that certain parts, such as the transmission or steering mechanism, need special oils made just for them. Show your child where these are located, and what the oil containers look like and any special funnels needed, such as the one for adding transmission fluid.

Demonstrate How Oil Works

• To show your child how oil works, you can use two drinking straws. One straw should be slightly smaller than the other, so that it can slip inside the larger straw with not much room to move. Alternatively, you could use a straw and a slightly smaller dowel rod. Let your child move the straw up and down on the inside shaft. Ask him to notice how hard it is to move the straw. Next, rub the inner straw or rod with some vegetable oil from the kitchen. Have your child try moving the inside rod or straw up and down in the outside one again. He will be able to observe that the oil makes it easier to move.

Filtering

• Add some play sand or bits of dirt to your lubricating oil. Ask you child to move the shaft now, and to see what happens to the movement. There are a couple of possible outcomes: the shaft will become harder to move again, or the bits might even scrape through the straw. Explain that dirt isn't good for your car, either, and that is why it has to get its oil and filter changed to keep the bits out of the moving parts in the engine.

Cooling influence of Oil

• Ask your child to rub his hands together briskly. Discuss how warm they become after being rubbed together. Explain that engine parts get warm that way, too, if they don't have enough oil. Pour a small amount of vegetable oil, baby oil or hand lotion in your child's hands. Ask him to rub his hands together again. Ask him if they warmed up as fast this time. Explain that oil reduces friction, and that friction causes heat. Oil is, therefore, important in helping keep an engine cool.