Spark Plug


The cars have a lot of important parts and essential for its proper functioning, one is the spark plug , a piece that turns out to be essential to start up a car because it is responsible for the engine of the same can remain ignition by transmitting the ignition spark into the propellant combustion chamber .

What is a spark plug?

The spark plug is a fundamental part in the electrical part of the engine of a car and are responsible for making the mixture of fuel and air within the cylinder can be exploited to thereby the is achieved movement proper of the piston .

  • Spark plug features
  • Story
  • Types
  • Parties
  • How the spark plug works
  • What is it for
  • Breakdowns
  • Spark plug maintenance
  • Importance

Spark plug features

Among the main characteristics that can be observed in spark plugs, the following are mentioned:

  • They are built with porcelain and with some other metallic elements .
  • It does not have any moving parts .
  • It contains a central electrode which is separated from the spark plug by means of an insulator.
  • Its lower part is made of threaded metal .
  • It has the ability to create uniform heat flows .
  • It has a very good thermal graduation .
  • It is resistant to mechanical , thermal and electrical stress .


According to records, it was Edmond Berger who first invented a spark plug, however, he did not patent it. Later, Jean Joseph Étienne Lenoir , a Belgian engineer, succeeded in developing the first internal combustion engine and is credited with inventing the spark ignition system. A short time later, Gottlob Honold developed the spark plug in the factories of a renowned manufacturer, Robert Bosh , and it was he who first patented the spark plug.


Spark plugs can be classified depending on their thermal degree which is determined by the manufacturers thanks to a series of laboratory tests. The types of spark plugs that exist are the following according to their resistance :

  • Bare resistance spark plug : found in diesel engines and with the naked eye you can see the electrical resistance.
  • Protected resistance spark plug : in this case, the resistance is covered with a magnesium oxide sleeve to make the heat more easily transmitted.

Depending on the size of the current arc , the spark plugs can be:

  • Normal opening spark plugs: their arc has a measurement of up to 0.9 millimeters and is the simplest of all spark plugs.
  • Large opening spark plugs : the arc is usually 2.05 millimeters long and requires the presence of high voltage coils in order to function properly.

Depending on the type of material with which they are manufactured, there are the following types of spark plugs:

  • Made of platinum or iridium : they have a higher resistance and have lower conductivity.
  • Of copper : type plugs are better known and have a good driving power.

According to the type of fuel they can be classified as follows:

  • For gasoline : they are the most used.
  • For diesel : they are quite different and have a glow tube in the cylinder head to send the heat into the combustion chamber.
  • For gas engines : they produce high wear on the electrodes due to oxidation.


The parts that make up a spark plug are the following:

  • Terminal : It is located on the top of the spark plug and is attached to the ignition system.
  • Insulator : it is made of sintered aluminum oxide and is responsible for providing adequate electrical insulation and the mechanical support of the main electrode while producing a larger spark.
  • Insulating tip : it is a piece that enters the combustion chamber and can withstand between 650 ° C and 6000 volts.
  • Metal casing : it is used to dissipate the heat produced by the insulation and allows it to pass towards the head of the motor.
  • Seals : are necessary to ensure that there is no leakage in the combustion chamber.
  • Central electrode : it is connected by means of an internal cable and by ceramic resistors that can reduce the noise caused by the spark. They are made of copper, chromium or noble metals.

How the spark plug works

The spark plug works as a kind of spark of electricity which is emitted by a small space enables the ignition is believed the combustion step essential to start a vehicle . When the engine pistons are set in motion, a combustion of air and fuel occurs . Then, the piston will move down the cylinder, sucking in this mixture and then rising again towards the spark plug so that the mixture is compressed.

Then, when the piston is at its top dead center , the spark plug is responsible for emitting a spark through which the mixture is ignited . Subsequently, the piston is forced back to produce energy and then it is pushed up again to be able to expel the exhaust gases , then the whole process is repeated again.

What is it for

The spark plug of a car is a fundamental part of it that serves to be able to conduct the current that is needed to start the engine . In addition, they are responsible for absorbing the heat that is produced within the combustion chamber in order to prevent the engine from overheating, this they do by distributing the heat to the car’s cooling systems, causing an adequate balance in temperature .

They also serve to trigger the spark ignition of the car, help achieve proper performance of engines and collaborate in maintaining a fuel consumption that is optimal, helping the same time to prevent gases pollutants are issued in large quantities.


Among the main breakdowns that can occur in the spark plugs, the following are mentioned:

  • Spark plugs with existing buildup white : when this situation occurs, indicates that the engine may have a number of failures at high speeds and occurs due to a loss of oil or because it is used fuel of poor quality.
  • The electrodes have carbon deposits : in this case the spark plugs are black and the car may have problems when starting . It can also cause a reduction in vehicle power .
  • Overheating : it occurs when the spark plug overheats when it is working and therefore there is a significant loss in the power of the car .
  • Porcelain Insulation : The porcelain in the spark plug breaks due to sudden changes in temperature .
  • Preignition : this is a very serious spark plug problem and is caused by very high temperatures that are registered in the cylinder, which may be due to poor treatment of the engine or lack of cooling.
  • Presence of rust : this situation usually occurs in places where humidity levels are very high or when the vehicle is not used for a long period of time, causing loss of engine power and problems starting the vehicle.

Spark plug maintenance

Keeping the spark plug in optimal condition is essential in order to keep the vehicle working properly . Being able to identify symptoms of problems is necessary to avoid serious complications. In order to detect faults, the spark plugs must be removed from the engine and for this, it is best to seek a professional in the field. In addition, it is necessary to follow all the recommendations given by the manufacturer .

Despite the fact that for proper maintenance the spark plugs can be cleaned, it is always advisable to change them with new ones, as this can prevent damage related to performance , power and the engine . The spark plug must always be clean , without any type of corrosion and without excess oil on its sides, it must also be complete and it must have all its parts complete.

It is important to mention that the spark plugs must be replaced when they reach 60,000 kilometers in gasoline vehicles and 120,000 kilometers when they are diesel cars . It is also important to make sure that the new parts are completely original and that they are also in good condition.


The spark plug is of utmost importance in gasoline engines, it is responsible for lighting the spark that is necessary for the mixture of air and gasoline in the internal part of the cylinder in the car. It is thanks to the spark plug the engine can operate correctly and is also the responsibility of making the fuel has a good performance . In addition, it is thanks to it that it is possible to find some of the abnormalities that occur within the engine .

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