Automotive Features Explained

Spark Plugs: The Ultimate Cheat Sheet


Every time you turn the key in your vehicle’s ignition, you start a series of reactions that work to turn your engine on. Your spark plugs act as the middle man in this scenario; they deliver electricity from the ignition – where you turned the key – to the combustion chamber of the engine – where all the magic happens.

One the electricity gets to the chamber, it ignites the compressed fuel-and-air mixture that sits inside, which then creates a spark. That spark powers up the pistons, which are responsible for your wheels turning and your car moving.

If the plugs don’t make the spark, then your car can’t start… So their job is pretty important.

What Causes Your Spark Plugs to Stop Working?

Several things can cause your spark plugs to stop working properly.ga_blog_sparkplugs-01

  • Age: Spark plugs have a life span of around 45,000 kilometers. Any older and they start malfunctioning.
  • Corrosion: Oil and unburnt gas can build up on your plugs and corrode them, which stops the transfer of electricity from the engine.
  • Residue: When an engine burns oil, it creates an ashy residue that can  bog down spark plugs.

Signs Your Spark Plugs Need to Be Replaced

If any of these scenarios are happening regularly, your spark plugs might be to blame.

  1. Your car won’t start. If your spark plugs are dirty or old, they can’t deliver the spark that’s needed to start your engine.
  2. Your car won’t accelerate. Sometimes a listless engine just needs a fresh pair of plugs.
  3. You’re paying more at the pumps and it’s not just because gas prices have gone up. Corroded spark plugs can reduce your vehicle’s fuel economy.
  4. Your engine doesn’t idle smoothly anymore. If your engine is making unusual noises while it idles – such as knocks, sputtering or hiccups – it could be your spark plugs.
  5. Your car’s engine misfires. If your engine stumbles and then picks back up again, it means things aren’t firing properly.

Fixing Your Spark Plugs

If you ignore your spark plugs, it can lead to bigger issues. For instance, malfunctioning spark plugs can cause damage to your catalytic converter, which is responsible for reducing the harmful compounds that are found in your vehicle’s emissions… like carbon monoxide.

If you’re experiencing any of these issues, it’s important you have a service technician check it out. Book a service appointment and make sure your spark plugs are in working order.


If you have any questions or comments, leave them for us down below!