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 1,000 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: Bank one and two in rich conditions, CEL on

If the mass air flow sensor has failed, unfortunately cleaning will not resolve the issue. I would recommend having your mass air flow sensor tested with a digital multimeter or scan tool using the manufacturer's suggested procedure to determine if...

Q: What Wears Out Engine Spark Plugs?

Spark plugs are used to ignite the air/fuel mixture in the combustion chambers of every engine. The plugs are subjected to extreme heat, combustion pressures, and vibration. These are just some of the factors that contribute to spark plug wear....

Q: Starting issues

Hey there. Thanks for writing in about your 2005 Pontiac Grand Prix. There are many possible causes for a car not to start. Based on your description, however, I believe there is something wrong with your ignition system. I would...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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...