How Much Do You Know About Small Engine Parts?

By: Steven Symes
Estimated Completion Time
4 min
How Much Do You Know About Small Engine Parts?
Image: shutterstock

About This Quiz

Get out your magnifying glass and try to remember detail engine schematics. The tiny parts in engines abound! You might think of engines as large, smelly, loud objects sitting under your car hood, but some of the parts are actually very tiny.

When engines were first created, they were relatively simple machines that people marveled at. The fact is, they were loud, smelly, unreliable, weak, and wouldn't last long. That's far different from the engines we get in cars today. We've become conditioned to expect most engines to last the life of a vehicle, thanks to all kinds of innovations in their design. 

Of course, with all that innovation comes complexity. Modern engines contain hundreds of parts, but as a trade-off they are light years ahead of early car engines. If you've ever rebuilt a newer engine, particularly one with fuel injection, you know just how many little components are inside them. Forgetting to install just one little part, or not installing it exactly as you should can result in serious engine problems. Every last component in an engine is important, even the small things you might think are somewhat expendable. 

Just how much do you know about the little things in an engine? Take this quiz to find out! 

What does the knock sensor monitor for?
if anyone is knocking on the hood
when the engine knocks into the transmission
even slight signs of detonation problems
The knock sensor sends voltage signals back to the ECU, which uses those to determine if the timing for the engine needs to be retarded, before damaging pre-detonation occurs.
vibrations in the engine mounts
On some engines that require routine valve adjustments, this part helps speed up the process.
valve adjuster flux
flux capacitor
valve cover
Valve covers are designed to take the hassle out of adjusting valves somewhat regularly. They come off by removing just a few bolts and go back on with similar ease.
valve access hole
You must remove this to get the old oil out of the engine.
oil cone
oil fill hole
oil pump
oil drain plug
Sometimes this can be the hardest part of doing an oil change, if you don't have a wrench that's up to the challenge. You can also use penetrating lubricant on the bolt and let it sit for a little while.

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This should provide an accurate reading of how much oil is left in the engine, but you might get your hands a little dirty.
oil meter
oil overflow reservoir
oil dipstick
When the engine is turned off, you can use the dipstick to see if the oil is full enough, or if you need to add a quart or two. You'll need a rag or paper towel to clean the dipstick off to get an accurate reading, though.
oil collection pan
This is the thing that ignites the air and fuel mixture in the engine.
alternator
ignition wire
electrical magnifier
spark plug
It's amazing to think the spark plugs in your engine are constantly producing sparks to trigger mini explosions in the cylinders, which then turn the wheels.
What acts as a regulator of when exhaust gases escape the combustion chamber?
escutcheon
bolt gasket
exhaust valve
Valves open and close passageways. In this case, the valve opens and closes the pathway in the cylinder head that connects to the exhaust manifold.
O2 sensor

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What ensures the piston won't let any gases escape around the edges once it's in the closed position?
piston gasket
piston seal
Piston seals are usually made of rubber or a similar substance, so they create an airtight seal that won't let exhaust gases or the air and fuel mix to seep out in the least.
head gasket
magic 8 ball
Where does the air temperature sensor sit in a car?
air intake system
The air temperature sensor gives feedback to the ECU, since this information can affect how much fuel should be sprayed by the injectors. The colder the air, the more oxygen-rich it is.
exhaust system
combustion chamber
cylinder head
What is the part that keeps the connecting rod and piston together?
lynch pin
litch pin
gudgeon pin
With all the force exerted on the piston and connecting rod each time the air and fuel ignite, the gudgeon pin has to be strong and durable, otherwise the engine would fail quickly.
safety pin

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What regulates exactly how much fuel makes its way into each cylinder?
luck
magic screws
fuel rail
fuel injector
The fuel injector has an incredibly precise nozzle, so the car's ECU can regulate with precision how much fuel should make its way into the cylinders at any given moment.
What exactly does the crankshaft position sensor monitor?
if the crankshaft slips
where in the engine the crankshaft is located
if the car is on a slope
how fast the crankshaft is spinning at any given time
Sometimes called a crank sensor, this sensor is vital in managing the engine's timing, which is especially important in a variable valve timing setup.
If you find oil in the spark plug tubes, what are you likely going to need to replace?
the engine
spark plug regulators
spark plug tube gaskets
Just how hard replacing the spark plug tube gaskets is really depends on the engine, just like so many other components.
spark plug auto gappers

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Besides cosmetics, what's one reason you might replace the engine oil cap?
It blew up.
The cap has spun into the stratosphere.
The seal has started leaking.
If you look at the underside of your engine oil cap, there's a rubber or silicone seal that should create a tight seal. If that fails, you could conceivably replace it, but you might find it easier to just buy a new cap.
You like to burn money.
What does a cold start injector pipe provide?
more air
extra fuel
To help starting the car up when the engine is cold, some designs use a pipe that's triggered by the temperature of the coolant and/or a timer circuit.
extra coolant
additional oil
What are the two kinds of valve lifters?
electronic and analog
reverse and traditional
hydraulic and solid
You might hear valve lifters referred to as a tappet or lash adjuster, but it's the same thing. Just remember that solid valve lifters need to be adjusted periodically.
split and binary

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Which direction does a valve spring pull the valve?
left
right
open
closed
Most people don't think at all about the valve springs in their engine, even though this part is absolutely essential for proper compression.
What is one thing the idler pulleys do?
spin the belts
oil the timing belt
guide the engine drive belts
Idler pulleys keep the belts that drive the alternator, water pump, power steering pump and AC compressor at the proper tension and moving at the right points around the engine compartment.
lubricate the camshafts
When reinstalling the cylinder head bolts, what must you be sure to do?
spread butter on the threads
keep them loose enough to jiggle the engine cover
torque them to spec
Not only do you need a torque wrench to tighten the bolts enough, you should always follow the manufacturer's recommendation for the tightening pattern.
turn them counterclockwise

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What small engine part acts as a gate, regulating the flow of air and fuel into the cylinders?
flow regulator
flux capacitor
exhaust valve
intake valve
While the camshaft triggers the motions of the valves, it's the actual valves that either let the gases flow in the engine or sit.
What is the function of the piston ring?
guard against oil leakage
to maintain an airtight seal with the cylinder walls
The piston ring is usually made of rubber or a similar substance and it sits in a groove that runs around the sides of the piston, forming an airtight seal that the air/fuel mix and exhaust gases shouldn't flow past.
stop backfiring
maintain proper engine temperatures
The water outlet on your engine basically is what simple device?
a bowl
a spoon
a pipe
It might sound simple, but the water outlet on your car's engine is essentially a pipe that connects to the water jacket, letting hot coolant flow out of the engine and toward the rest of the cooling system, namely the radiator.
a banana

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What actually touches the gudgeon pin in the connecting rod?
the cylinder
lots of packing grease
oil
connecting rod bushing
The purpose of the connecting rod bushing is to reduce vibrations in the engine, but they're made of a durable metal, so they don't dampen as much as rubber bushings would.
What is the purpose of the camshaft knock pin?
It holds the camshaft sprocket in the right position.
The camshaft knock pin fits on the end of the camshaft. Not only does it hold the camshaft sprocket where it should go, the pin lines up the two parts correctly.
It allows you to write with the camshaft.
It records camshaft movements.
It contains a lethal injection.
What part is most likely worn if your engine is burning oil?
gudgeon pin
cylinder seals
valve seals
Replacing valve seals is actually a pretty easy job, but it is a little on the tedious side. If you must pass emissions in your area, doing this will be essential.
exhaust vortex

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If a camshaft seal fails, what will happen?
loss of compression
The check engine light comes on.
The engine will leak oil.
At the end of the camshafts in a car's cylinder head is a rubber seal, designed to keep the oil inside the engine. Normally these last a long time, but in older engines the seal may fail.
Your mom calls you to dinner.
What large part do the main bearings hold in place inside the engine?
camshaft
crankshaft
Even though they're small, the main bearings have a difficult and critical job, considering the crankshaft is converting the up-and-down forces of the pistons into a rotational force.
piston
valve
Why do most automakers use T-T-Y head bolts?
They cost less.
They increase compression ratios.
Clamping loads are more consistent.
Not every engine has torque-to-yield head bolts, but just about every automaker uses them when the cylinder head is made of aluminum.
They look better.

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An oil leak at the top of a cylinder head could be coming from which part?
valve cover gasket
The valve cover is located at the top of the cylinder head, making it a likely source of the leak. Of course, the oil cap is another potential origin.
ignition wires
engine mount
engine hanger
Each valve spring must be fitted with a keeper and what else?
modulator
retainer
The valve spring, keeper and retainer work together to create a constant amount of pressure, which snaps the valve closed tightly.
capacitor
lid
What part directly actuates a rocker arm?
spark plug
ignition key
pushrod
Essentially, a rocker arm is an oscillating lever that's actuated by a pushrod, which is actuated by the lobes on the camshaft.
valve spring

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What's the point of the valve guide bushing?
to look cool
to guard against detonation
it adds strength to the valve
reduce engine vibrations
Engines have plenty of moving parts, and that means vibrations are inevitable. The valve guide is the cylinder that the valve moves back and forth in. This bushing just tries to reduce vibrations created by that movement.
A non-interference engine design means you don't risk damage to what critical small parts if the timing is off?
camshaft
valves
The valves in a non-interference engine never occupy any space the pistons do, even at different times. That means they're never at risk of colliding, which can damage the pistons as well as the valves.
head gasket
spark plugs
What wheel with teeth connects directly to the crankshaft?
hub
crankshaft pulley
Sometimes called the harmonic balance wheel or crankshaft sheave, is an essential part of the engine's timing system.
differential
flywheel

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What are the uneven sections on the camshafts called?
spoons
lobes
Camshafts aren't perfectly straight shafts, otherwise the engine wouldn't run properly. They contain uneven lobes that determine when, how much and for how long the valves open.
peninsulas
gnomes
What part helps the ECU know how much oxygen is contained in each cubic inch of air as it flows into the cylinders?
O2 sensor
knock sensor
air temperature sensor
The air temperature sensor sits in the air intake, gathering data that helps the ECU measure how much gas should be injected into the cylinders. The colder the air, the more oxygen atoms in each cubic inch of it.
throttle
You Got:
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