We all know that spark plugs are a very important part of making a gasoline powered car run. They literally put the combustion into the internal combustion engine; when the spark plug fires, it causes the explosion that moves the pistons that make the car go. So when the combustion is a little late, or doesn’t fire at all, it can lead to all sorts of problems with the way your car’s engine runs. Old spark plugs can lead to things like a rough idle, worse gas mileage, difficulty starting the car and even worse acceleration. The good news is that changing those spark plugs may give that car exactly what it needs to smooth out some of those engine issues.
Check Under The Hood Before You Make a Spark Plug Commitment
One of the first—and we mean very first—things to take into consideration when you are getting ready to change your spark plugs is to go over to your car, open that hood, and see where the spark plugs are located on your engine. If they are arranged in a convenient location on the top of the engine and easily accessible, go ahead and continue on your spark plug journey of discovery.
If, however, you are one of the lucky people whose spark plugs are located in an inconvenient location halfway down the engine block and wedged between the radiator and the Flux Capacitor, you may want to think long and hard about whether or not you want to have your local auto shop take care of changing those spark plugs for you. After you have considered how much cursing you want to do over the course of the next several hours, and have decided you want to deny your favorite car garage your business, we can proceed.
Ready To Get Started? Changing Your Spark Plugs Begins Here
Before you start disassembling things, always make sure to brush any dirt and debris off of your engine; your air compressor or a clean paintbrush should help with this. The holes that the spark plugs come out of lead directly into the engine, so your want to make sure you don’t drop anything in there to muck up that engine when you are supposed to be fixing it. You also want to make sure your engine is cool to the touch before you start. You are removing parts from the section of the engine where the explosions happen. Don’t burn yourself.
To change the plugs you will need a few fairly simple tools including a ratcheting socket wrench (and any extenders or flexible joint adapters to make sure that the wrench’s socket can get to the spark plug), a spark plug socket, and a spark plug gap tool.
The first thing to do when removing the spark plugs (after you’ve done your initial debris removal) is to gently remove the wires from the back of them. Depending on when they were last removed, you may have to wiggle them free. Be careful while removing them so you don’t have to replace them as well. Be sure to take note of which wire is connected to which spark plug so you can reconnect the same one to the same place in the future.
Now is a good time to double check that there is no new loose dirt or grime that can fall in the engine. Grab your air compressor hose once more. Now you can use your socket wrench to remove the old spark plugs.
What To Keep An Eye Out For On the Old Spark Plug
While it is good to ask whether or not your spark plug is bad or worn out before you change it, the fact of the matter is that spark plugs are pretty cheap. If you’ve gone to all of the effort of taking them out of your engine, you might as well put the new ones in regardless of what the old set looks like.
That being said, any spark plug that has been in an engine will have some level of discoloration on it, because of the whole causing controlled explosions part of their job. You will definitely want to change the plug if it has any sort of white buildup, if any parts of it are bent, broken or missing, or if they are black with soot. If anything on the old spark plug looks extra strange—such as broken parts that can’t be blamed on an inexpert extraction from the engine—it is probably a good idea to have a professional make sure there isn’t something wrong with your engine.
Is This The Part With the “Mind the Gap” Joke?
An important part of installing the new spark plugs is to make sure the gap where the spark is produced is the correct width. Even if the plug is brand new, if the gap is too wide or too narrow, it can cause the engine to run as if the spark plugs are old. Though you can check the old spark plugs with your gap tool to see what their gap is, there is no guarantee that the gap on the old plugs is actually correct and hasn’t been knocked out of alignment. The best way to verify what the gap should be is to check your owner’s manual. Keep this gap requirement in mind when you are buying your new spark plugs.
A good rule of thumb when buying your new plugs—other than making sure you get the correct size and gap and all of that—is to never get spark plugs of a lower quality than those that you took out. Your car is getting older no matter how well you treat it, and you won’t thank us if you install a lesser quality plug and have lesser quality performance. Most plugs nowadays have a fixed gap, so make sure to purchase the correct one for the job. It’s still a good idea to use your tool to verify it is where it needs to be before you install them.
Time For Installation: Don’t Forget Your Future Self
If you had a rough time getting your old spark plugs out, do yourself a favor for the future and be sure to put a little dab of anti-seize lube on the threads before screwing them into the engine—many spark plugs will have a little packet included. Or you could buy the fancy anti-seize spark plugs and skip yourself a step. Use your socket wrench to firmly tighten the spark plugs back into the engine block. If you have a torque wrench, now would be a good time to use it. If you make it too tight or too loose, you will probably have a bad time. Check your manual for the torquing details.
Once the spark plug is secured where it needs to be, all you need to do is pop those spark plug wire boots back on to the tops of the spark plugs in the correct order you took note of earlier, and you should be ready to hit the road with your new smoother, potentially more fuel efficient ride.
