Skip the auto shop - Our mechanics make house calls

Q: How Do Spark Plugs Work in an Engine?

asked by on

How do spark plugs work in an engine?

Spark plugs are used to ignite the air/fuel mixture in the combustion chambers of every internal combustion engine.

To accomplish this, spark plugs have two electrodes between which a high voltage spark will jump. One electrode is located in the center of the plug and one electrode is attached to the side of the plug.

The high voltage comes from an ignition coil and contains anywhere from 5,000 volts to 40,000 volts. The high voltage is necessary to overcome the air turbulence, compression pressure, and the air gap of the spark plug during the combustion cycle. The spark jumps from one electrode to the other. This spark ignites the air/fuel mixture in the combustion chamber. The combustion continues until all the fuel has been converted into heat and increased cylinder pressure. This is what creates the power inside of an engine.

Each spark plug fires one time for every two revolutions of the engine crankshaft.

If your vehicle is down on power or is getting less fuel economy, a fresh set of spark plugs may be in order. If you need help with this, schedule a visit with a certified technician who can check out the situation and replace your spark plugs if necessary.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. How Do Spark Plugs Work in an Engine?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car idles rough, gas smell - 1988 Mercedes Benz 560SL

Check to see if the air filter housing has been sealed properly and that the mass air sensor has not been damaged by dirty air getting by the air filter assembly. If it has, then replace the mass air sensor...

Q: My 97 yukon turns over but doesn't start I took the fuel pump it's not that

You will need to have the computer scanned to see if you are getting a crankshaft and camshaft sensor signal and giving the ignition spark. If not then replace the sensor that is not giving the signal so your engine...

Q: Glow plug

Like the Check Engine Light, the glow plug light on late model diesels can come on to indicate a problem in the engine control system. Even when the light is out, there should be a trouble code stored in the...

Related articles

How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...