Illustration for the article titled How and Why to Test Your Vehicle's Spark PlugsPhoto: Ohm1999 (Shutterstock)

When most drivers turn the key or push a button to start their vehicle, they are unlikely to go through everything that needs to happen for their engine to start. And while the process seems so simple to us today (especially when it’s literally a push of a button), so many things happen under the hood that they all have to fit together and function properly for you to push the button on the street.

Although small spark plugs play an important role in starting and running your vehicle, be sure to replace them when they have passed their prime. Not sure it’s time? Then you need to test them. Here’s why it matters and how to do it.

Illustration for the article titled How and Why to Test Your Vehicle's Spark Plugs

What do spark plugs do?

It is probably a good idea to have a basic understanding of what spark plugs actually do. Here is a brief explanation of Mike Cote at Auto Anything::

A spark plug is essentially an electrical device that fits into the cylinder head of your engine and “ignites” there to ignite the fuel. The connector is connected to the ignition coil, which creates the high voltage needed to ignite the fuel and create combustion in your engine. No spark plug means no combustion, which means you won’t be going anywhere without one.

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Why test a spark plug?

When Your indicator light comes on– or you have another problem with your engine that is not immediately noticeable – there can be a variety of faults. But Hank O’Hop from The Drive explains that when troubleshooting engine problems it makes sense to start with the simplest and easiest solution and from there prepare for more complicated problems. And when you’re dealing with a misfire, the easiest way to start is with the spark plugs.

Illustration for the article titled How and Why to Test Your Vehicle's Spark Plugs

How to test a spark plug

While you can certainly leave this to the professionals, it’s easy enough to do at home as well. In his article in The Drive, O’Hop walks us through two different ways to test a spark plug at home: a ground test and a multimeter test. You will need the following:

  • Spark plug puller (for older vehicles without coil packs)
  • Multimeter (for resistance test)
  • Spark plug connector
  • Sockets (for cars with coil packs)
  • A spark plug that is known to work

We’ll let O’Hop take it from here, so Check out his article on The Drive for the rest of the steps – including how to do it to make everything as safe as possible.