Spark Plugs FAQs
1.What is a spark plug ?
A spark plug is a rod of metal that tops off the combustion chamber of a vehicle’s engine.
2.How big is a spark plug ?
An individual spark plug is about as big as a human pointer finger.
3.How many spark plugs does a car need ?
Only cars with internal combustion engines need spark plugs, and cars get one spark plug per cylinder.
For example, a four-cylinder internal combustion engine has four spark plugs, while an eight-cylinder engine has eight spark plugs.
4.What does a spark plug do ?
As the name implies, a spark plug supplies a small electrical spark. It ignites the fuel inside the combustion chamber at a precise moment, which pushes the cylinder down and then moves the car forward.
5.How does a spark plug work ?
Spark plugs are vital to the operation of the engine cycle and the internal combustion that drives the engine. Without these little rods of metal, your car would malfunction.
The combustion chambers need precise timing of several parts to work properly, and spark plugs are one of the parts required.
6.Where are the spark plugs on my car's engine ?
Typically, spark plugs are covered by electrical wires on top of the pistons. Look for anywhere from four to eight wires (depending on the engine size) in two rows somewhere on top of the engine. You’ll have to pull off one of the electrical wires to see the top of the spark plug.
7.What are spark plugs made of ?
Most spark plugs consist of an electrode composed mostly of copper and an insulator made of aluminum oxide ceramic to prevent errant discharges outside of the combustion chamber. The shell around the electrode is made of steel wire.
Other spark plugs may consist of different types of metals.
8.What does a spark plug look like ?
One end is tapered to accept the wire from your car’s electrical system, while the other end has a little metal hook designed to ground the spark coming from the electrode that sticks out of the center of the metal thread.
9.How much do spark plugs cost ?
Sold in sets, spark plugs range in price from $16 to $100, depending on the brand, how many you need, and the materials in the spark plugs.
10.Why do my car's spark plugs wear out ?
They typically wear out when carbon, the main leftover of combustion, builds up over the electrode and causes the spark to misfire.
Reasons for carbon build-up on spark plugs include:
- A dirty air filter causes less-than-ideal air to enter the combustion chamber.
- Excessive driving at low speeds, which makes your engine run less efficiently.
- Too rich of a mixture of air and fuel, which causes inefficient combustion.
- Dirty fuel injectors, causing dirt to enter the combustion chamber.
- Idling your vehicle for too long.
11.What happens when spark plugs go bad ?
An engine misfires due to a delay in the spark coming from the plug. The misfire causes the piston to not produce enough power, and it affects your engine's ability to maintain peak fuel efficiency. If you don't fix the problem soon, it could cause long-term damage to your engine.
12.What are signs I need to change my engine's spark plugs ?
Your car may display one or more signs that indicate you need to replace spark plugs in your engine.
- Trouble starting. This could happen due to a damaged or worn spark plug wire or spark plug misfiring.
- Worse fuel mileage. Have you been filling up your gas tank more often? Poor fuel mileage could be due to a misfiring spark plug or two. Misfiring spark plugs may reduce your car's fuel efficiency by as much as 30 percent.
- Rough idling. Your car's engine normally idles quietly and without any shaking. You might hear your engine making rattling, knocking, or pinging noises due to wayward vibrations.
- Check engine light comes on. Have your chosen technician diagnose the problem.
- Slow acceleration. If your car doesn't respond as it normally does when you accelerate, a problem in the combustion chamber may be the culprit.
13.How often should I change spark plugs ?
Whenever your owner's manual maintenance schedule tells you to. But spark plugs may last anywhere from 30,000 to 90,000 miles, depending on the vehicle.
14.Do new spark plugs make my car run faster ?
New ones for your car can increase fuel economy and make your engine run at its peak without any knocks, pings, or stalls.
15.Are some brands of spark plugs better than others ?
No, the quality is based on the materials.
Iridium spark plugs may last up to 25 percent longer compared to platinum ones.
16.What types of metals go into spark plugs ?
The electrode is typically made of copper.
The grounding electrode, which is the curved piece of metal on the end, is usually made of platinum or iridium.
