How to Change Spark Plugs in 6 Easy Steps

(Updated on April 16, 2020)

Anyone driving a traditional car with a gasoline engine will understand the importance of spark plugs. These are the parts which create the spark that ignites the air and fuel mixture in the internal combustion chamber of the engine. What you may not realize is that spark plugs tend to wear out very quickly. Each time a spark plug generates a spark, it wears down a little bit of the metal on its two electrodes. After a while, the electrodes will be so eroded that they won’t be able to carry the spark to the combustion chamber. This is when you will experience negative symptoms like a bad fuel economy, engine misfires, weak engine performance, and things like that.

How to Change Spark Plugs

When you need to replace your spark plugs, you can either go to an auto shop and get it professionally done or you can replace them yourself. Fortunately, replacing spark plugs is not a skill that requires you to be an expert auto mechanic. You just need to understand the basic steps of the job. Once you learn them, you will be able to replace your own spark plugs and save money on labor costs.

Below are the top 6 steps for changing the spark plugs of your vehicle by yourself.

1) Gather Your Tools – Unless you have a V6 engine, the tools that you will need should be the same for everybody. These tools will include a spark plug socket, torque wrench, ratchet, universal joints, and spark plug gap gauge. Refer to your owner’s manual to find out more information on the tools that you will need. Any hardware or auto parts store should sell these tools. You may even be able to find a special spark plug kit which has all these essential tools already in it.

2) Locate the Spark Plugs – The owner’s manual will help you locate the spark plugs of your vehicle, although they are usually located on the top of the engine. So, open the hood of your vehicle and locate the top of your engine. Take off the ignition coil so that you can reach the spark plugs. If you see big wires connected to the spark plugs, turn the boot of each one and take them off.

3) Blow Compressed Air – Your spark plugs will likely have crud and debris on them. You will need to remove this crud with compressed air if you have it available. This will reduce the chances of the crude from entering the cylinder once you take off the spark plugs. If you don’t have compressed air, just be very careful when you unscrew the spark plugs. Use the socket for this task. Of course, unscrew and replace them one at a time. This will make the process easier to manage.

4) Check the Spark Plug Gaps – Use the spark plug gauge to check the gap between the two electrodes of each spark plug. If the gap is the correct distance, according to your owner’s manual, then you can proceed with the installation of the spark plugs.

5) Install the Spark Plugs – Screw on the new spark plugs one at a time. Use a torque wrench to ensure the torque specifications of the spark plugs match what is required for them in the owner’s manual. It is important that you tighten the spark plugs just right with the torque wrench or else the spark will not jump properly for the ignition.

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6) Reattach the Ignition Coil – Now all you need to do is reattach the ignition coil and the wiring if applicable. The boot of the spark plugs may need a bit of dielectric grease too.  Apply this grease before reattaching the ignition coil. This will help ensure there are no misfires when you go to start the engine after this process is finished.

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