1. Ditches
   Wells
2. Ravines
   Holes

If you want to pull the spark plugs out of your engine, you'll need a special extension on your socket wrench. It needs to have a soft component to not break the plugs, and must be long enough to reach them.

1. Yes, they line up with specific spark plugs
   No, they're all the same
2. Yes, they're color coordinated
   No, you can put them anywhere

Automakers actually make the ignition wires different lengths to help take the guesswork out of where each one goes. Your spark plugs don't all fire at the same time, so you need to match the correct plugs and wires, or your engine will run rough, if at all.

1. Engine smoke
   Bad air quality
2. Cold weather
   Oil leak

You can tell a lot by pulling your spark plugs. The ashy substance might be caused by an oil leak, like what happens when your head gasket blows. Although not as likely, it might be from bad fuel, which means you should go to a better gas station in the future.

1. Your engine is burning rich
   The air is too hot
2. You speed too much
   Your engine is blown

Black, sooty buildup on your spark plugs is usually called dry fouling by mechanics. It usually means your engine is burning rich. If that's what you see, check the air cleaner to see if it's clogged, because that's likely the cause, and that's a super simple fix to take on yourself.

1. When you pour gas on your car
   When your spark plugs look black and wet
2. When you spill your drink
   When you pour water in the engine

Usually, wet fouling means your head gasket has blown, so the oil flows into the spark plug wells or cylinders. Another cause might be bad piston oil control rings or other problems with the valve train. It's not as likely, but this could be the symptom of your engine running super rich.

1. You're using leaded gasoline
   A squirrel got into your engine
2. You're using banana fuel
   Your car needs a break

This symptom is super uncommon, because leaded gasoline is really only used for racing these days. Lead fouling could cause misfires as you push the RPMs, like when you accelerate hard, which is a real problem when you're competing in motorsports. If you're not planning on racing, this won't apply to you.

1. You speed too much
   You brake too hard
2. It's made of clay
   Improper installation

Usually, when the center electrode is melted, it's from not tightening the spark plug in the threads all the way. You won't get as much power from your engine when this happens. Sometimes, this problem can be caused by hot spots in your engine, which usually means pre-ignition issues.

1. It's a dalmation
   You put in the wrong spark plug
2. Overheating issues
   You bought the wrong brand

Several issues can cause overheating, including ignition timing that's over-advanced, a lean air/fuel mixture, too low of a spark plug heat range, or a vacuum leak. Probably the most common problem is that the cooling system in your car isn't functioning properly, which is something you need to fix or plenty of other problems can pop up.

1. No, they ship gapped
   Yes, they're not always the correct setting
2. No, they work with any gap
   Yes, spark plugs are always the wrong gap

Because spark plug makers usually are using the same spark plug for all kinds of engines, they can't gap them all to the right setting. Sure, you might get lucky and the gap the plugs ship with works for your engine, but you really should check and set the gap with a gap tool, which takes like thirty seconds.

1. Decreases it
   Increases it
2. Doesn't change it
   Makes it spit

If you live or are going to drive where the ambient humidity is high, you might need a higher voltage to ensure your engine runs correctly. That usually means upgrading the ignition coil, if the one you have isn't rated to put out more.

1. The crankshaft
   Your foot
2. The wheels
   The earth's rotation

In breaker-point ignitions, which are the oldest style out there in modern cars, the distributor runs as the crankshaft rotates. The great thing about this setup is figuring out problems and fixing them is easy.

1. More power
   Less power
2. Greater fire risk
   The world ending

Lower resistance means the coil can make more power. Not only is more power always good, it makes the coil more reliable, since it can go longer without failing, which is also a really good thing. In racing, cars only have extremely low resistance coils.

1. More power
   Better reliability
2. Even combustion
   All of the above

Some modern engines use this unique design to ensure all the fuel in each cylinder combusts. It leads to better efficiency and power, plus reduces deposit buildup. A second spark plug creates a twin flame front, so there are no hot spots in the cylinders. These are all good things.

1. One that's never the same length
   A wire that can't throw a baseball consistently
2. Wires that work for all engines
   One with tight and loose copper wire

The alternating tightly and loosely wound copper wires around the plug wire provides a definite advantage. It works to get rid of most radio frequency interference, which is created by the ignition system, resulting in optimal resistance and performance.

1. Really fun injection
   Rare fine ignition
2. Rule fine internet
   Radio frequency interference

All electrical systems in a car create RFI, or electrical noise, including the ignition system. If you're using sensitive electronic equipment, RFI might interfere with your readings. Things like spark plug caps and resistor wires can help cut down on this factor, so you don't have to deal with the issues.

1. When the manufacturer recommends it
   When your car stops working
2. Each time you change the oil
   Once a month

Every engine is different, so you really should rely on what your car's manufacturer says. Just look in the owner's manual for a spark plug change interval, or go to the automaker's website for that info. They'll know about how long spark plugs will realistically last.

1. When the compression ratio changes
   When you repaint the car
2. When you put on a new muffler
   Only when you use NOS

As compression in your engine rises, so does the heat. The whole point of spark plugs is to get rid of the heat in the cylinders, so you'll have to switch to a colder heat range by getting new spark plugs, otherwise you could suffer some performance issues. This would be for big modifications, not small ones.

1. If you're running a turbo
   If you're running a supercharger
2. If you want to do burnouts
   If you have an on-board diagnostic computer

Because spark plugs and the ignition system can generate electrical noise that will mess with computers, you should use resistor style plugs if you have such a setup. The same is true if you have two-way radios, a GPS system, or other onboard electronics.

1. When the spark happens too early
   When the engine stumbles
2. When the electrodes fire
   When the distributor fires

Anytime the spark plugs fire and ignite the air-fuel mixture in the cylinders too early, or before the ignition timing you or the vehicle manufacturer has set, this is called pre-ignition. It can cause all sorts of problems, including fouling the plugs, reducing power, and creating engine deposits.

1. By feeling
   By just knowing
2. Torque wrench
   You hear a click

All spark plugs come with a specific torque rating. If you tighten a plug too much, it can break and you have a real mess on your hands. A loose spark plug can trigger overheating and other damage.

1. Maybe
   No
2. Yes
   Always

Many people think swapping the spark plugs in your engine will make more power. The only time they really help to improve horsepower is when your current spark plugs are worn out. You do need different spark plugs as you increase engine power, but the spark plugs don't make that extra power.

1. Your engine working
   Backfiring
2. Uncontrolled air-fuel burn
   When an engine explodes

Detonation is absolutely not good for your spark plugs, since it can break them. The cause of detonation is too much heat and pressure in the cylinder, which just makes the air and fuel ignite before it should.

1. Top of the compression stroke
   Beginning of the intake stroke
2. End of the exhaust stroke
   None of these

Ideally, the spark happens right before the piston reaches the top of the compression stroke, resulting in the most power and best efficiency possible. Ignition anywhere else in the process will mean your engine doesn't run as well.

1. The same time
   Later
2. Earlier
   Twice each cycle

Fuel always takes about the same amount of time to burn. To adjust for engine components moving faster, the spark plugs need to fire sooner. The term for this adjustment is spark advance, allowing for higher and higher RPMs in engines.

1. Timing
   Temperature
2. Size
   Power

As you retard the spark on your engine, that means the plugs fire closer to the top of the compression ratio. Be careful, because too much retardation can move things back so far you suffer power loss.

1. Length
   Size
2. Gap
   Shape of the ceramic tip

Whether you need a hot or cold spark plug really depends on your car. Hot plugs feature a smaller contact area on the tip, while cold plugs increase that contact area so they run at lower temperatures. See your car owner's manual to decide which you need.

1. One
   Two
2. Three
   Four

Ignition coils are shockingly simple devices, no pun intended. Basically, they're a high-voltage transformer that features two wires, with one being the primary coil. The secondary coil is wrapped around it.

1. Cylinders
   Spark plugs
2. Ignition coil
   Wall outlets

The distributor performs a variety of functions. It's most important task is to transfer voltage from the coil, sending it through the correct wire to each of the cylinders in the right timing order. A bad distributor can make your car run rough, or not at all.

1. Looks cool
   Keeps things cool
2. Ground the plug
   Keeps the spark at the electrode tip

You absolutely don't want spark to happen anywhere but the tip of the electrode, which is what the ceramic insert guarantees will happen. The insert performs another vital function, helping to burn off deposits that would otherwise build up and diminish the spark.

1. The weather
   Exactly where the pistons are
2. Sports scores
   Your mother's house

Modern cars have an onboard engine control unit or ECU that will always know where the pistons are. This enables it to time the spark at just the right time, so you get ignition at the peak of compression, and not before or after.

1. Your mother
   The gas pedal
2. The weather
   The ECU

It's the ECU's job to manage the ignition coil, through a series of transistors. This setup means you get precision control, which is why so many modern cars have switched over to this approach for an ignition system.

1. Half the speed
   A third of the speed
2. The same speed
   A tenth the speed

Gears on the bottom of the distributor and the crankshaft mesh together. They're purposely designed to spin the distributor at half the speed, since it doesn't need nearly as many revolutions to perform its job.

1. Lead
   Snake
2. Arm
   Electrode

Some people will call the cables that connect the distributor cap to the spark plugs just wires. Other people think that's a confusing name, preferring to call them leads. You just should know both terms, even if you prefer to use one of them.

1. All the time
   When the engine isn't running
2. When it gets cold
   At freeway speeds

When the engine is running, the distributor powers the ignition system, while the alternator takes care of everything else electrical. A bad battery will keep your car from starting because no electricity, or not enough, will reach the spark plugs.

1. Your day
   Your life
2. The flow of electricity from the battery
   The government

As you turn the key in your car, the ignition switch opens up a connection between the battery and the ignition system. Once you close that off by not twisting the key, the battery can start to recharge via a connection with the alternator, so it's ready to start the engine up later.