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People usually don’t give their spark plugs lots of thought until they face an issue where the mechanic tells them it needs replacement. As small as they look, these parts play an incredibly important role in how your car functions. In fact, without properly working spark plugs, your car more than likely wouldn’t be able to run at all. This article will give you a closer look at why your spark plugs are so important, including what they do and how to know when it may be time to replace them.

What is a Spark Plug?

Also known as a "sparking plug", is a device used in delivering the electric current to the air-fuel mixture in the combustion chamber. It’s connected to the ignition coil, as the electricity flows through the coil, a voltage difference develops between the electrodes on the spark plug.


The electrodes:

They must be able to resist high temperatures, and the insulator separating them must withstand high temperatures and also electric stress up to several thousand volts.

Spark-gap length:

This affects the energy of the spark, and the shape of the insulator affects the temperature of operation. When the temperature is too cool, operation leads to carbonization and short-circuiting of the gap; and when it’s too hot, there may be resignation.

What does Spark Plugs do?

To make sure gasoline ignites and runs through the air intake manifold, which leads up into each cylinder of your vehicle’s engine. This process is called the spark ignition cycle.

1. Spark ignition cycle:

A spark ignition cycle happens every time you turn your car on. In order to work properly, your vehicle’s spark plugs need a good connection with the distributor cap and coil after they have been installed in an oxygen-free electric environment for 15 minutes or more before the installation of new spark plugs.

2. When Connected:

The spark plug can push hot gas from a cylinder and it will cause a misfire in your engine. If this happens often enough, you may need to replace your car’s spark plugs with new ones – or even re-wire them into the distributor cap for more effective connections.

When do I need to change my Spark Plug?

  • As plugs approach the end of their life, the gap between the two leads begins to widen, which leads to reduced efficiency and the possibility of misfiring.
  • If your plug corrodes to the point where it breaks, it could do serious damage to the interior of your engine cylinder, which leads to an extremely expensive repair to get it fixed. Be sure to consult your vehicle’s owner’s manual to see how long of a lifespan your spark plugs are rated for. Never let your spark plugs go past their rated mileage.


How to know you have a faulty spark plug?

Below is a list of the most common symptoms that tells you that you have a worn-out spark plug or a spark plug that has fouled and need to be replaced:

1. Lack Of Acceleration

A spark plug is composed of materials that work together to produce a spark hot enough to ignite the air-fuel mixture. When those materials wear out, the effectiveness of the spark plug is reduced, which can significantly reduce the acceleration of the vehicle. If your vehicle feels unresponsive and the accelerator has lost its sensitivity you might consider a service with a change of Spark Plugs to get things up to speed again.

2. Rough Idle in your Engine:

If your Spark Plugs are failing, your engine will sound rough and trembling when running at idle. This can cause vibrations to your car. That is an indication of a spark plug problem in which a cylinder misfires only while idle.

3. Trouble Starting:

If you have trouble starting your vehicle, it could be a sign your spark plugs are worn. The engine's ignition system is composed of multiple individual components that must work together to function properly. This can be due to a Spark Plug failure, and without that crucial spark for ignition, you’ll be stuck where you are.

4. Misfiring Engine:

The engine misfires due to an issue in the ignition system, when it does that, it immediately cuts out and feels jerky because the cylinders are not firing correctly. This can lead to an uncomfortable ride and higher emissions.

5. Hesitating Engine:

You may notice the engine hesitating while accelerating. In this case, the engine is not responding correctly to the driver. It may suddenly surge in power, then slow down. Again, this can lead to an uncomfortable – and potentially dangerous – ride. The engine is working inefficiently, sucking in more air than is usually needed in the combustion process, causing continual stop-start motions.

6. High Fuel Consumption:

Are you filling up more than you used to? Failing Spark Plugs can take a bite out of your fuel efficiency. While a fully-functioning spark plug helps burn fuel efficiently in the combustion cycle. When this occurs, your car can achieve better-than-average fuel economy. So, a simple change of Spark Plugs could be the solution.