Things to know when changing your spark plugs | DIY - Hagerty Media

Keeping your car in peak running condition is a good idea for a multitude of reasons. A basic tune-up can expose critical information about parts of your engine that are otherwise difficult to inspect. Spark plugs are a critical part of any tune-up and a great entry-level DIY project. Kyle Smith is here with all the tips you need to swap out your engine’s spark plugs.

The tools

While any socket that fits the spark plug on your engine will work, a dedicated spark-plug socket has two convenient features that a standard socket doesn’t: a small piece of rubber to hold the plugs in place and thinner walls to fit in tighter spaces. Many basic mechanics toolsets include the two most-common spark-plug sizes but, in a pinch, you can add a piece of appropriately-sized rubber hose inside a standard deep socket.

Another tool we’d recommend is a short chunk of fuel hose that fits over the ceramic of your plugs. This is a great thing to have nearby for starting the threads when installing the new plugs. Sure, you could use the socket you have on hand, but we’ve found that approach increases the likelihood of cross-threading or otherwise damaging the threads of the cylinder head. Those threads are precarious to repair with the engine still assembled, so an ounce of prevention is worth the pound of cure.

The process

Let’s not make this job more complicated than it is: Unthread the old plugs and thread in the new ones. Simple, right? Yes, but a few tips can make the process even easier. Label the spark-plug wires before you pull them from the plugs, or swap them out one at a time to avoid crossing the ignition wires. Also, take the time to clean any debris from the base of the spark plugs before removing them. This precaution keeps any grit or other nastiness from falling into the combustion chamber.

Stop to learn

The most important step in a spark-plug swap is to stop and inspect the old plugs; their condition will yield a surprising amount of information about your engine’s health. Is there excessive oil buildup, heavy wear on the ground strap or electrode, or checking on the insulator? Now may be the time to dive into the root cause. If you are lucky, the old plugs will have a nice toasted marshmallow color on the insulator and no extreme wear on the ground strap or electrode.

Changing spark plugs is a simple DIY project that will keep your beloved car cruising happily for years to come, so what are you waiting for? Get out your tools and tackle this quick job. While you’re in a “get ‘er done” mood, be sure to subscribe to the Hagerty YouTube channel to never miss a new video.