The Engine Quiz!

By: Staff
Image: refer to hsw

About This Quiz

It's under the hood of every car, truck and SUV (unless the vehicle is electric), but how many people really know how an engine works? Do you know a spark plug from a fuel injector? Test your auto smarts in our engine quiz.

What does ECM stand for, and what does it do?

ECM is the engine control module, and it’s the computer that manages the engine’s functions.

Why don’t we use steam engines for cars anymore?

Internal combustion engines are a lot more efficient than external combustion engines, which is why steam engines fell out of favor for cars.

A turbocharger is:

<a href='http://auto.howstuffworks.com/turbo.htm' style="font-weight: bold;">Turbochargers</a> and <a href='http://auto.howstuffworks.com/supercharger.htm' style="font-weight: bold;">superchargers</a> are both air compression systems. They pressurize the air moving into the engine, increasing the engine's power.

What are the three functions of engine oil?

Most people know that engine oil lubricates to help with metal-on-metal contact, but it also helps cool and clean the engine as it circulates.

What is an octane rating?

The octane rating relates to how much the fuel can be compressed before it spontaneously ignites. A rating that’s too low can cause the engine to run poorly.

What are two of the main advantages to a 4-cylinder engine?

The 4-cylinder engine did not become popular in the United States until the 1980s, when Japanese manufacturers demonstrated how small and efficient it could be.

In a car engine's cylinder, valves let fuel in and exhaust out. The ______ moves these valves.

A <a href='http://auto.howstuffworks.com/camshaft.htm' style="font-weight: bold;">camshaft</a> is a rotating rod that uses a series of lobes to open and close the valves. Most modern engines have overhead cams -- the camshaft is directly above the valves.

What are the two main components of the engine cooling system in most cars?

With a water-cooled engine, which is the most common type of cooling system, the radiator and water pump circulate water to absorb heat and move it away from the engine.

Why does engine oil need to be changed?

Because engine oil cleans the engine, it picks up dirt and debris as it circulates, which gradually reduces its efficiency.

What might happen if water gets into your gas tank?

Water will prevent the gasoline in the system from burning properly, which will cause combustion problems in the engine, which will prevent the car from starting or cause it to run poorly.

What is an engine’s redline?

An engine’s redline, which is shown on the tachometer, determines its maximum revolutions per minute, or RPM.

There are three basic failures that can happen in an engine: bad fuel mix, lack of compression and:

Lots of things can go wrong under the hood, but the big three in the engine involve fuel, compression and <a href='http://science.howstuffworks.com/fire.htm' style="font-weight: bold;">fire</a> .

Which of the following commonly uses air-cooled engines?

Many motorcycles are powered by air-cooled engines.

What happens if your car leaks or burns off all of its oil?

Oil lubricates the pistons so they can move smoothly inside the engine, and without oil, the engine will seize.

Modern cars use internal combustion engines, but some early models used external combustion engines. What is one example of an external combustion engine?

Steam engines were most commonly used in trains and boats, but did power some types of cars.

A car uses a four-stroke engine. The four strokes are:

In the intake step, a cylinder gets some fuel and air to burn. Then, it compresses the fuel to make the combustion step (the explosion) more powerful. In the last step, the cylinder releases its exhaust.

A car engine's job is to:

There's a lot of heat in a car's engine -- and a lot of exhaust coming out of it -- but these are byproducts of the engine's true purpose. An engine has to use fuel to create motion to move the <a href='http://auto.howstuffworks.com/tire.htm' style="font-weight: bold;">tires</a>.

What are the three common ways to deliver fuel to an engine?

Carburetion, port fuel injection and direct fuel injection all get the fuel where it needs to go.

When you turn the key to a car, the starter motor:

The starter motor has a big job -- it has to overcome friction, cold weather and other factors to get your engine started. If it fails, nothing happens in the engine when you turn the key.

What are the three common ways to arrange an engine’s cylinders?

An engine’s cylinders are most often arranged in a line (inline), in two rows set at an angle (V) or in two opposite banks (flat).

A crankshaft's job in an engine is to:

When <a href='http://science.howstuffworks.com/gasoline.htm' style="font-weight: bold;">gasoline</a> ignites in a cylinder, the piston moves in a straight line. Your wheels, on the other hand, need to turn. The piston moves a connecting rod, which turns the crankshaft, producing the rotational motion.

A timing belt or timing chain links these two components together so that the valves are in sync with the pistons:

A timing belt or timing chain links the crankshaft to the <a href='http://auto.howstuffworks.com/camshaft.htm' style="font-weight: bold;">camshaft</a> so that the valves are in sync with the pistons.

A device that works on the same principle as a car engine is:

In a both <a href='http://science.howstuffworks.com/spud-gun.htm' style="font-weight: bold;">spud gun</a> and a car engine, you ignite a small amount of fuel, releasing a large amount of energy. (And it's equally unwise to get in front of a moving car or a loaded spud gun.)

Why does a diesel engine get better mileage than a gasoline engine?

Diesel has a higher energy density than gasoline, meaning that each gallon burned makes more power.

What are two other terms for engine knock?

Pinging is another way to describe the sound, and detonation describes what’s causing it.

What is the steam engine’s main advantage?

A steam engine just needs to create steam, so if it can burn, it can be fuel. That's why in those old silent movies, when the hero runs out of coal to power the train, he starts burning his coat and hat.

Which of these cars features a popular example of an air-cooled engine?

The Volkswagen Beetle was designed with an air-cooled engine specifically for its simplicity.

What’s another name for the four-stroke engine cycle?

The Otto cycle is named after its inventor, Nikolaus Otto.

When a car's engine is running, power to operate the radio, CD player, headlights and windshield wipers comes from the:

A large battery is used to start the engine when you turn the key and run the vehicle's electrical system. The alternator is connected to the engine by a belt and generates electricity to recharge the battery.

Name one of the causes of engine knock.

There are several causes of engine knock, and experts say that installing the wrong spark plugs is a common problem.

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