The Engine Quiz for Dummies

By: Dave Davis
Estimated Completion Time
6 min
The Engine Quiz for Dummies
Image: Jetta Productions Inc

About This Quiz

While you don't need to know how to build a clock to know what time it is, you do need to be able to tell time to make sense of the hands' positions. The same goes for automobiles. You don't have to be a mechanical genius or know the intimate details of the internal combustion engine, but drivers should know a bit about the machine they're entrusting with their day — and in some cases — their lives. Do you know your OBD port from your dipstick? This quiz will put your knowledge to the test! 

Major repairs should be left to the professionals, but a car owner who knows how to perform the basic functions of vehicle maintenance will be able to skip some of the more expensive trips to the mechanic. And, when it does come time for a major repair, you'll be a more informed consumer, rather than just handing over the keys and saying, "My car is broke." Reputable mechanics would like a little more information; disreputable mechanics will see a payday. Either way, you're not helping your case by not understanding at least the broad strokes of what's going on under the hood.

So, are you up on your knowledge of your car's engine or could you use a refresher course? What does it mean when white smoke is coming out of your tailpipe. What exactly is the oxygen sensor sensing and why? At the end of this quiz, you'll either be more confident in your skills or will have learned some valuable lessons, so c'mon in and show us what you've got!

Question 16
Rpsycho / rambo182 / E+ / DigitalVision Vectors / Getty Images
What does the alternator do in a vehicle?
It provides electric power to your car's components.
It's used when you switch from "drive" to "reverse."
It's another name for the battery.
It was used in older AM/FM radio systems.
Correct Answer
Wrong Answer

While the car's battery provides the initial spark that gets the vehicle running, the alternator takes over the electrical charging duties from there. The alternator, so named because it generates alternating current (AC), provides power to the starter, ignition coil and all the vehicle's electric systems, such as the headlights, stereo, dashboard lights and other items.

Question 19
Zoonar RF / rambo182 / Zoonar / Getty Images Plus / DigitalVision Vectors / Getty Images
The temperature needle on your dash is edging toward the red zone — what's going on?
You have a coolant leak.
You have a bad radiator fan.
You have a bad thermostat.
All of these are possibilities.
Correct Answer
Wrong Answer

The engine produces a lot of heat when it's running, and when the system that draws that heat away fails at some point, your temp needle is going to start moving (or, less helpfully, your light is going to come on). It's time to visit the garage and see what's going on under the hood.

Question 24
Jose Luis Pelaez Inc / DigitalVision / Getty Images
What's the dipstick's function in your car?
Nothing. Modern cars don't have dipsticks.
It's for checking your tire's air pressure.
It's for checking the transmission fluid level.
It's for checking the oil level.
Correct Answer
Wrong Answer

The humble dipstick is one of the best ways to check on the health of your car by making sure your engine has enough oil and that the oil is clean. Every driver should be able to use the dipstick because it's an easy process; pull it out and wipe it clean, put it back into its pipe, take it back out and check the level and the color of the oil. Done!


Question 7
Wiki Commons by Ilya Plekhanov
Smoke Break! What does black smoke coming out of your tailpipe mean?
Your fuel/air mix is too rich.
You've got a fuel tank leak.
Your muffler has gone bad.
Your car is overheating.
Correct Answer
Wrong Answer

If your car is running too rich — meaning there is too much fuel in your fuel/air mix — black smoke will start to appear in your exhaust (and also might be putting off a "rotten egg" smell). Common causes for this could be a leaking fuel injector, a faulty engine sensor or a bad fuel pressure regulator.

Question 18
Tjanze / rambo182 / E+ / DigitalVision Vectors / Getty Images
You go to start your car and nothing happens — what's the first thing you should do?
See if the battery terminal clamps are loose.
Call the mechanic.
Jumpstart the car.
Buy a new car.
Correct Answer
Wrong Answer

The clamps that attach the battery terminals to the electrical system need to be in full contact to complete the circuit and get your car started. When you turn the key and nothing happens — no lights and no sound — pop the hood and check to make sure things are attached correctly. The fix could be easier than you think!

Question 26
Wiki Commons by Collard / rambo182 / DigitalVision Vectors / Getty Images
In the automotive world, what is a gasket?
A chamber that catches oil
A filter that strains out impurities
A seal between parts in your engine
The lining of the trunk
Correct Answer
Wrong Answer

Gaskets are mechanically simple but vital parts of your car's engine. Usually consisting of a steel center coated in a rubberized material, gaskets not only provide a cushion between metal parts of the engine but provide a seal that keeps oil and other fluids from going where they should not go. The head gasket is probably the most famous member of the gasket family.


Question 23
Wiki Commons by Willdre
The solenoid, brush gears and field coil are all part of the ...?
Flywheel system
Starter motor
Oil pump
Correct Answer
Wrong Answer

When you turn the key to start the car, you are activating the starter motor, which gets the internal combustion process started until the engine can take it from there. The starter motor is a complex machine in its own right and while you only use it at the very beginning of your journey, you're not going anywhere without it.

Question 1
Prapass Pulsub / Moment / Getty Images
What ultimately happens when you run your engine without oil?
It overheats.
It seizes.
It makes a lot of noise.
Nothing. It's a scam perpetrated by Big Oil.
Correct Answer
Wrong Answer

When a car's engine runs, there are a LOT of moving parts involved, and some of these parts come into contact with others. Without oil to lubricate the works while the engine is running, those parts start to grind together. While this will cause excess heat and noise, the engine will eventually just stop working and seize. Check your oil!

Question 33
Wiki Commons by Bill Wrigley
Which of these best describes a car's radiator?
It's a relic of a bygone era.
It's located in the back of the engine.
It's a heat exchanger.
It's mostly electronic.
Correct Answer
Wrong Answer

The car's engine puts out a lot of heat, and the radiator is one of the most critical parts in getting that heat away from the motor. Coolant is pumped through the car's engine and this hot liquid eventually makes its way through the thin tubes in the radiator which cools it by transferring the heat to the outside air.


Question 8
Wiki Commons by Dvortygirl
Where does oil go when the car is not running?
Nowhere. It stays put.
It goes to the radiator for cooling.
It returns to the oil pan.
It goes to the cylinders to keep them lubricated.
Correct Answer
Wrong Answer

Oil is circulated throughout the engine when the motor is running to keep all the pieces nice and lubricated. When the engine is shut off, it is stored in the oil pan, located under the engine. If the pan gets damaged through the wear and tear of an active life, attentive owners will start to notice puddles of oil forming under the car.

Question 10
How a Car Works via YouTube
What is the heaviest part of the engine called?
The ballast chamber
The engine block
The cylinder head
The head gasket
Correct Answer
Wrong Answer

The engine block is, basically, a big hunk of shaped metal that has precision holes drilled into it. The engine block, which is sometimes called a cylinder block, is the bottom part of the motor and contains the cylinder bores, along with passages for oil for lubrication and coolant passages to keep the heat down.

Question 13
Cravetiger / Moment / Getty Images
What does the serpentine belt do in an automobile?
It's the central unit of the steering system.
It provides power to a number of systems in the car.
Trick question — it's a part of a tractor-trailer truck.
It warns animals on the road that your vehicle is approaching.
Correct Answer
Wrong Answer

The serpentine belt snakes around (giving it its name) and connects the alternator, air conditioning compressor, power steering pump and other components to the crankshaft pulley, and provides power to keep them running. Older cars had many belts to perform all the functions this one belt now pulls off.


Question 30
Juanmonino / E+ / Getty Images
What's the function of an oxygen sensor in your car?
It maintains cabin temperature.
Helps to maintain the correct fuel/air mix.
It monitors tire pressure.
It monitors engine temperature.
Correct Answer
Wrong Answer

The oxygen (O2) sensor measures how much unburned oxygen is left after the engine's combustion process. The car's onboard computer can take this information and change the ratio to make sure the most efficient mix is being used. Symptoms of a bad O2 sensor are a rough idle and difficulty in starting.

Question 12
schlol / rambo182 / E+ / DigitalVision Vectors / Getty Images
What do connecting rods actually connect?
The engine to the transmission
The camshaft to the crankshaft
The pistons to the crankshaft
The wheels to the axle
Correct Answer
Wrong Answer

Connecting rods are what connect the piston to the crankshaft. Because they can rotate at both ends, they allow the up-and-down motion of the pistons to be converted into the rotational motion of the crankshaft that goes to spin the wheels. When you hear of someone "throwing a rod," these are the rods in question.

Question 6
Wiki Commons by Arp
In automotive technology, what does "OBD2" mean?
On-board diagnostics
On-board displays
Oxygen-bound disruption squared
Trick question! It's actually a "Star Wars" character!
Correct Answer
Wrong Answer

On-board diagnostics is the way a car can report to its mechanic or owner what's going on with it. Through the use of a scanner that plugs into the vehicle's OBD port — usually located under the dashboard near the steering column — the user can read codes that tell the health or status of the various sensors within the car.


Question 21
Stockbyte / Getty Images
Smoke Break! What does bluish-gray smoke coming out of your tailpipe mean?
You need a different grade of gasoline.
Your air filter needs to be changed.
Your engine is burning oil.
You need a tune-up.
Correct Answer
Wrong Answer

Blue-gray (or sometimes white-gray) smoke is a symptom of your car's engine burning oil. This could mean that you've got too much oil in the engine (which is important to remedy but easy to fix), or your engine's piston rings are worn or you've got worn valve seals (not as easy to fix — you're going to need a professional).

Question 2
kevinjeon00 / E+ / Getty Images
What type of engine is found in the typical car on the road today?
External combustion
Steam turbine
Internal combustion
Correct Answer
Wrong Answer

Although electric engines are becoming much more common, the standard car is powered by an internal combustion engine. With these, the fuel/air mix is injected into the cylinder where it is combusted (think of it as a cylinder-sized explosion), which moves the pistons, the wheels and you down the street.

Question 25
Wiki Commons by Christopher Ziemnowicz
What's the function of your car's harmonic balancer?
It sets the treble and bass of your stereo.
It reduces engine vibration.
It's a decoration to put around your rearview mirror.
Trick question! There's no such thing.
Correct Answer
Wrong Answer

The harmonic balancer has a new-age name, but it's all about mechanical practicality. Since the internal combustion engine fires in succession and not continuously, the engine would vibrate terribly with this "on/off" power generation. The harmonic balancer, connected to the crankshaft, evens this out by spinning smoothly and providing stability.


Question 5
Wiki Commons by Mgiardina09
What control function can the car's ECU perform?
The engine's idle speed
The fuel/air ratio
The timing of the intake and exhaust valves
All of the above
Correct Answer
Wrong Answer

The engine control unit, or ECU, of the modern car is the computer that maintains engine performance of the vehicle. Using an array of sensors, the ECU keeps a check on how your engine is operating and can make changes to the fuel/air mix, the idle speed, the timing of the valves and more to get optimal performance from the beast under your hood.

Question 3
Prapass Pulsub / Moment / Getty Images
The engines of most cars today are powered by...?
Diesel fuel
Good intentions
Correct Answer
Wrong Answer

Most cars today use gasoline as fuel for the combustion that makes the wheels go round. Although inventors experimented with other fuel sources, gasoline — which was actually a byproduct from the process of making kerosene — eventually got the nod because of its high-energy potential and the fact that it mixes well with air for the combustion process.

Question 34
Wiki Commons by IJB TA
Where is the cylinder head located?
Within each cylinder
At the back of the engine
Underneath the engine block
On top of the engine block
Correct Answer
Wrong Answer

The cylinder head is bolted to the top of the engine block — separated by the head gasket — and forms the upper part of the cylinder's combustion chamber. Made of aluminum alloys in modern cars, symptoms of a cracked cylinder head can include oil and coolant loss, smoke and overall cruddy performance. The cylinder head shown here is from a 1987 Honda CRX Si and includes a single cam, rocker arms, valve springs and other components.


Question 29
FangXiaNuo / E+ / Getty Images
When your mechanic says your car has a vacuum leak, what's that mean?
You probably have a broken hose.
Your power windows no longer function.
Oil is getting into places it shouldn't.
Your AC is not operating properly.
Correct Answer
Wrong Answer

Your engine runs most effectively when airflow is carefully maintained and monitored. When you have a cracked hose, a leaking gasket or seal or another way air is being let into the system where it shouldn't, your car may idle roughly or too high, the engine may stall or you may hear a squealing sound.

Question 28
Wiki Commons by Christopher Ziemnowicz / rambo182 / DigitalVision Vectors / Getty Images
In your engine, fuel injectors are ...?
Used to get fuel from the tank to the engine
Used to get fuel into the cylinders
Another name for a carburetor
Used to make sure fuel is clean before being used
Correct Answer
Wrong Answer

Fuel injectors are small nozzles used to bring fuel into the cylinder that, when mixed with air, is ignited in the internal combustion process. Most modern cars — those from the 1980s onward — use fuel injection systems, which replaced carburetors because of their better performance and increased fuel efficiency.

Question 4
Rana Dias / Moment / Getty Images
What does the spark from the spark plug actually do?
Provides the engine's timing
Powers the AC and sound system
Ignites the combustion process
Powers the headlights
Correct Answer
Wrong Answer

In a gasoline engine, the fuel/air mix does nothing until it receives a spark generated by the spark plug. When the spark hits, the mixture ignites and moves the pistons. Spark plugs can be made up of different materials — copper, platinum or iridium can make up the electrode, while the insulator (the white part) is a shell usually made of an aluminum oxide ceramics.


Question 22
levente bodo / Moment / Getty Images
When you look at your car's RPM — revolutions per minute — what are you really measuring?
How fast the cylinders are spinning
The rotation of the wheels
How fast the throttle is spinning
The rotation of the crankshaft
Correct Answer
Wrong Answer

The crankshaft changes the up-and-down motion of the pistons in the engine into rotational energy that ultimately drives the wheels. RPMs measure how fast the crankshaft is spinning. When the car is idle (not moving), the RPMs are somewhere around 1,000. The faster the engine runs, the higher the RPMs.

Question 9
Marin Tomas / Moment Open / Getty Images
What's the difference between a timing belt and a timing chain?
No difference — they're the same thing.
One is for domestic cars, and the other is for foreign models.
Belts are for summer, and chains are for winter.
One's a belt, and the other is a chain.
Correct Answer
Wrong Answer

The timing belt synchronizes the camshaft's and crankshaft's rotation and maintains the engine's timing or, more simply, it keeps all the players in the dance of internal combustion playing nice with each other. In older cars, this critical function was performed by a metal timing chain; newer cars have timing belts, which are quieter and less complicated.

Question 14
Hisham Ibrahim / Photodisc / Getty Images
Smoke Break! What does white smoke coming out of your tailpipe mean?
You've got a coolant leak.
Your AC is running too hard.
Your oxygen sensor is malfunctioning.
Your gas cap is loose or broken.
Correct Answer
Wrong Answer

Some white smoke when first starting the car, especially on cold days, is a normal result of condensation. When it doesn't stop, however, it most likely means that you've got coolant leaking into the engine's cylinders. This could mean a cracked cylinder head, a leaking head gasket or a cracked engine block. Time to go to the mechanic!


Question 20
Douglas Sacha / Moment / Getty Images
How often should you have the oil filter changed?
Every other time the oil is changed
Every 30,000 miles
Every time the oil is changed
You don't have to. The filter is self-cleaning.
Correct Answer
Wrong Answer

Oil is critical to your engine's well being, but dirty oil can start to damage its inner workings. The humble oil filter doesn't cost much but can add years to the life of your engine by keeping dirt, debris and other impurities out of the lubrication system. When you have the oil changed, they'll always change out the filter, as well.

Question 32
photoggin / E+ / Getty Images
An engine's air filter...?
... keeps dirt and debris out of the engine.
... can affect how the engine runs if it's clogged.
... is easily changeable.
All of the above
Correct Answer
Wrong Answer

The air filter is designed to clean the air coming into the throttle and keep dust, dirt, debris, pollen and other contaminants out of the engine where they can do damage over time. This part does need to be changed out regularly (every 15,000 and 30,000 miles, depending on conditions), but it's usually a very easy thing to do.

Question 15
Yaroslav Mikheev / Moment / Getty Images
What should you do when the "check engine" light comes on?
Ignore it. It'll go off eventually.
Immediately pull over.
Wait and see if any other lights come on.
You or your mechanic should check the car's diagnostic codes.
Correct Answer
Wrong Answer

This mysterious light could mean anything from your gas cap is loose to oxygen sensor needs to be replaced to your catalytic converter has gone bad. The on-board diagnostic (OBD) will let you know which one it is. When the light is flashing, however, that's a signal to visit your mechanic because there's serious trouble going on under the hood.


Question 31
schlol / E+ / Getty Images
What does a manifold do in a modern vehicle's engine?
It conducts current in the electrical system.
It moves gasses around the engine.
It connects the transmission to the engine.
It does a great many things.
Correct Answer
Wrong Answer

The internal combustion engine in a modern car has two manifolds — one for intake and the other for exhaust. The intake manifold brings air to the engine's cylinders which are mixed with fuel and then combusted. The exhaust manifold (shown here) takes these spent gasses and moves them along to make way for a fresh mix.

Question 35
schlol / E+ / Getty Images
How does a turbocharger work?
It forces more fuel into the combustion chamber.
It was part of the hand crank on older cars.
It increases the transmission's efficiency.
It forces more air into the cylinder.
Correct Answer
Wrong Answer

Turbochargers work by forcing more compressed air into the engine's cylinders, which allows for more fuel to be injected as well for a bigger explosion and more power. The turbine that makes all this possible is powered by the engine's exhaust gases. Although they perform similar functions, a turbocharger and a supercharger are mechanically very different.

Question 27
Wiki Commons by Marshmallowbunnywabbit
What is a "Hemi" engine?
It's an engine named after its designer.
It describes the shape of the engine's cylinders.
It's a type of racing vehicle engine.
It's just an adjective used to jack up prices.
Correct Answer
Wrong Answer

Normally associated with powerful, fast vehicles, a "Hemi" engine is one that has a hemispherical (or domed) cylinder head, rather than a flattened one seen in most vehicles. It provides more power but does have design drawbacks. Chrysler is perhaps the best-known manufacturer of this type of engine, but several other companies offer this as an option.


Question 11
kevinjeon00 / E+ / Getty Images
What does the crankshaft do?
It transfers the motion of the pistons into energy for the wheels.
It's a tool used to start very old vehicles.
It's part of the horn.
It holds the engine block in place.
Correct Answer
Wrong Answer

Without the crankshaft, the car's engine would run just fine but it would go nowhere. When the fuel/air mix is combusted, it drives the pistons up and down — a motion that is no good for getting the wheels to roll. The crankshaft is connected to the pistons by rods and is designed to convert that lateral motion into rotational energy.

Question 17
Henrik5000 / E+ / GettyImages
The engine, transmission, driveshaft and axles make up what system in your car?
Correct Answer
Wrong Answer

The powertrain is made up of all the parts that generate power in your car and transfer it to the wheels. When you buy or are given a "powertrain" warranty, this is the system covered. The drivetrain — the parts that connect the transmission to the drive axles — is part of the powertrain.

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Jetta Productions Inc