How to Change a Spark Plug: Do it Yourself

Spark plugs are small. Yet- the performance of your vehicle depends on them. Sometimes, people who are having car trouble- as in the car will not start- fear the worst. Yet, this could simply mean the spark plugs need to be changed. Keeping up with the routine maintenance on your car with things like changing spark plugs will keep your car running just fine, as well as get better gas mileage. Here are some tips on how to save yourself some cash by doing this simple task yourself.

First, you will need to gather the items you will need for the job, which probably means hitting your favorite auto parts store. On your checklist should be a 3/8″ ratchet, ratchet extensions, a sparkplug socket, a sparkplug gap tool and a small, clean rubber hose. And of course, your new sparkplugs. Be sure to ask which are right for your year, make and model.

Your obvious first step is to remove the old sparkplugs. (Be sure the engine is cooled off before you take on this task.) After you open the hood, you will need to find the spark plugs. They are located in a row alongside the engine. The plugs are attached to thick spark plug wires. Cars with V-shaped engines differ, as they will have plugs and wires on either side of the engine.

Next, begin changing the plugs. It is important to do this one at a time, as this will keep things in order. If you take them all off, and put them back on, you could do it in the wrong order, which could make the car run poorly- or even not at all. So, first, disconnect the plug from the wire by pulling on the small boot at the end of the spark plug wire. Once the plug is off, use your small hose to blow away any dirt or debris around the area. You do this because you do not want anything to fall into the hole once the plug is taken off.

Once disconnected use your socket and ratchet to remove the sparkplug, turning it counterclockwise. If the sparkplugs are set deeper, use the extension to help you get to them. Once removed, inspect the plug to make sure it needs changing, as sometimes they may not all need to be replaced. A good plug will be lightly coated with grayish-green deposits, so if it is heavily coated with dark, black deposits or if it looks damaged you’re right on track.

Next, gap the new sparkplug. You will start by looking in your owner’s manual to find the proper “gap” for your plugs. This could also be found on a sticker on the inside of the hood. If you can’t find either, as the auto parts store for the specs. Then, insert the sparkplug gapping tool in the gap between the metal center electrode and the metal side electrode of the plug’s tip. Look at the gapping tool’s ruled edge to find the gap’s measurement. If it is too big, you will have to bend the plug’s end with the tool to widen it. If you need to make the gap smaller, you can push the side electrode against a hard surface. After you make the necessary adjustments, measure once again just to be sure. If you need to, repeat this step until the gap matches your car’s specification.

Now that you have that done, you’ve got a feel for it. You will now repeat this process for each sparkplug. It will get easier with each plug you change! Once they are all in place, you will want to hand-tighten each plug. Then, you can use the socket to tighten them a little more. Do not overtighten though, as you will one day need to change these too. Then, replace each of the sparkplug wires. When finished, start the engine to make sure everything sounds good. If it does, you are ready to go!