A large factor of your vehicle’s smooth operation and longevity can be owed to the spark plugs.
These tiny elements make one of the biggest impacts of how your car runs. That is why spark plugs need to be checked and cleaned on a regular basis.
After knowing how to check and clean engine spark plugs, it is now time to learn how to change spark plugs. Here’s how to do-it-yourself this operation without messing things up!
Getting To Know Your Spark Plug
Spark plugs are responsible of igniting the air and fuel mixture inside the cylinder. Each plug has an electrode.
Like a small version of a lightning bolt, it forces electrons to arc across a gap through a high voltage. The phenomenon will create a spark – a major catalyst in the combustion process that makes your engine run.
The explosion produces great pressure that kicks the crankshaft into motion, transferring the power via the drivetrain, and putting your car into motion.
The electrical current is directed by the spark plug to go through a center electrode, consequently producing a spark across an air (electrode) gap, finalizing the circuit to a ground electrode.
Ceramic insulation surround the center electrode and ensures the current flows to the supposed direction and that no electricity is leaked.
Why Do You Need To Change Spark Plugs
There are a lot of factors behind less efficient fuel burn and inconsistent combustion. And mostly, it’s the spark plugs to blame.
Spark plugs can deteriorate over time due to regular use that results to carbon buildup. The fuel, oil, and heat can make the necessary gap too wide after a certain period of driving operations.
There also lots of symptoms indicating that you already need to check your spark plugs. Read the how to check and clean spark plugs to know more.
Experiencing these symptoms could mean that either you have to clean your spark plugs, or simply replace them if they are of no use anymore.
You need to check your sparkplugs if you have a hard time doing heavy acceleration or when your vehicle’s idle stumbles. A bad spark plug shows discoloration both on the metal and the ceramic parts.
Note: A typical spark plug can have a lifetime between 30,000 to 60,000 miles of use.
What Is The Best Spark Plug
Fundamentally, you should go to your manufacturer for the stock spark plug for your make and model.
However, there are also a few guidelines you can keep in mind when buying one. Spark plugs can come in an array of varieties that may satisfy your preferences.
- As a general rule, you get what you pay for. It means you generally can expect more longevity when you pay for a more expensive spark plug. However, there will only be a small difference as far as electrode is concerned.
- Spark plugs with the shortest life expectancy have copper material, while spark plugs with longer endurance have iridium materials.
- If you have a naturally aspirated engine that has no supercharger or turbocharger, it is advisable to go for a hotter plug so you can upwardly shift to a more efficient heat range
- If you have made certain installations such as aftermarket superchargers or turbochargers, it would be wise to go for one or two steps colder plugs.
- Having colder plugs doesn’t mean a lesser spark. It means a lower heat range for achieving the best efficiency if your car have forced induction power adders like the ones mentioned above.
- Whenever possible, it is wiser to go for the spark plugs with the best qualities money can buy. Spark plugs are quite affordable in the first place.
The Need To Gap Spark Plugs
Determining whether you need to gap your spark plugs is somewhat a hard question. For starters, you do NOT have to gap iridium plugs.
Improper handling of spark plugs while shipping can possibly close the gaps. So it’s important to check the spark plugs before you install them but gapping is optional.
Spark plugs are already pre-gapped so better be vigilant if the ones you received aren’t open enough. However, it would be rare to have damaged new spark plugs.
Again, iridium plugs need not be gapped. However, you can gap spark plugs with platinum or copper-made central electrodes.
First you need to determine the specific gap necessary for your vehicle’s engine by either simply Googling or asking anyone in-charge at your local auto supply/parts store. After which, you can check your electrodes with the use of a feeler gauge.
How To Change Spark Plugs
Now for the main course, here’s how to replace spark plugs. The process is actually quite simple and anyone can do this, pro or not.
1. Gather the right tools.
To start your new spark plug installation, you will have to get the following tools:
- Your newly bought spark plugs
- 12-inch socket extension
- Ratchet Wrench
2. Turn OFF your engine
This is an imperative step especially when it comes to safety. Always to keep in mind to turn off your engine first especially if you are a newbie in automotive do-it-yourself. Also, let your car achieve a lower temperature first before starting any operation. You don’t want to touch a hot engine.
3. Locate Where Your Spark Plugs Are
Find your spark plugs. Now open your hood and look for a set of thick rubbery wires that’s connected to your main engine. Following these rubbery wires will lead you to the spark plugs. Each spark plug at the end of each wire.
If you have a 4-cylinder engine, the spark plugs are arranged in a row in front of you at the TOP of the engine.
If you have a V8, the spark plugs are separated and are placed on both sides of the engine – four on the right and the other four on the left. You will have to reach down to access them.
Remember, follow the thick, rubbery wires as they will lead to your spark plugs.
4. Remove the Wire
A vital reminder in changing spark plugs is to NEVER pull ALL the wires out at once. Otherwise, you’ll face the dilemma of mixing them up.
Spark plugs fire in a specific order. With that in mind, it would be wiser to change them one at a time so you won’t have to deal with issues born out of carelessness.
- Start with the wire at the end of the row.
- Grasp the wire as close to the engine as possible.
- Now pull the wire off the end of that spark plug.
- If necessary, you can wiggle the wire first while grasping it tight just to get it off.
Note: In most cases of 4-cylinder engines, the end part of the plugs might be at a hole to where the wire is ‘plugged’. Regardless, just pull straight up at the reinforced base. You’ll find a long rubber boot out of the hole. Also, don’t forget to remove just one wire yet.
Related: How To Clean Cylinder Heads At Home
5. Remove the Spark Plug
After removing one wire, place the extension and the spark plug socket on your ratchet. On the inside end, you can see some black rubber or foam when you peek inside the spark plug socket. This one holds onto the spark plug while you try to get the thing in or out of your engine.
Note: You can improvise if ever your socket doesn’t have the gripper in there. Stick onto the inside of the socket a half-inch or less masking or electrical tape. This technique will allow your socket ‘grip’ more firmly on the spark plug.
Now set your ratchet wrench to loosen (counter-clockwise). Now slide your ratchet wrench over the end of the plug and push it as deep as it can. Now the old plug can be removed.
6. Observe the Spark Plug
How does your spark plug look? Being oily or white could mean certain issues. The spark plug can also look a little dirty on its end – a little, blackish soot. The article how to check and clean engine spark plugs discusses a list of proper diagnosis and indications of how well your spark plug is.
This is your chance to evaluate whether you need a new spark plug for that slot or you simply have to clean that one off.
Another purpose of this step is also to determine the right spark plugs to replace. Observe the setup of the end part of where you pulled the plug wire off. Some will have a metal cap on the end while others are just threaded like a screw.
After looking, make sure your new plugs have the same set-up like the initial ones.
7. Replace The Slot With A New Spark Plug
To make it ready for installation, set up the wire end of your plug like the old one. Also, you don’t have to worry about whether or not you have to gap your spark plugs. These days spark plugs come already gapped specific to your make and model.
However, you can always make sure by using some feeler gauge. But this one is really for die-hards who wants everything perfect for their car.
You can be trustful enough to trust your spark plugs are already gapped the way they should be.
When you doubt the way your packaged is shipped, you can always do a checkup. But if the packaged seems secure enough then you can conclude the spark plugs aren’t damaged and so they are already ready for installment.
- Now put the wire end of the plug in the socket.
- Hold just the extension.
- While holding just the extension, push the plug all the way in.
- Cautiously direct the spark plug into the hole.
- Be careful enough not to make unnecessary contacts especially to the gap. You don’t want to damage the plug or mess up the gap.
- With your hands, screw in the plug. Use your hands first in screwing the plug until it stops. Utilizing your hands first instead of using the wrench all the way can prevent cross-threading.
- This is where the wrench comes to use. Put the tool on the end and tight the plug snugly.
- Make the plug tight. You can also use a torque wrench to torque it to spec. If you don’t have the tool, just don’t overdo it. You don’t want to damage the soft metal due to over constriction.
- Set the plug wire back to place.
Related: Top 7 Best Torque Wrench
8. Finishing the Process
Now that you’re done with the first plug, it’s time to do the process to the rest of the plugs. After repeating all the steps to replace all your spark plugs, it’s time to close the hood and start your engine. Your engine should now have the right “vroom” sound like the first time you bought it.
Plug Wire Problem
If you ignored the warning above and pulled all the wires off at once, you might have mixed them unknowingly. No one can blame you, though, because pulling all the wires is quite tempting to do. But you know the wires are mixed when you notice any of these symptoms:
- You can’t start the engine
- The car runs rough
- The engine backfires; a really loud noise
What you have to do is to look up your engine’s firing order. Set your engine to Top Dead Center. Now correspond the order to the points on the distributor cap. After which, put them all back on.
This process gives you quite the hassle. To prevent this from happening in the first place, make sure you have carefully followed all the steps herein.
It is also advisable to inspect your plug wires. Spark plug wires are not spared to the possibility of wear.
They can also be broken so it would be better to diagnose possible problems early. Further, you can also learn how to install new plug wires. You can operate this process just by yourself!
Learning how to change spark plugs is yet another remarkable skill you can be proud to master.
You can also save lots of your hard-earned money by not seeking assistance of an auto mechanic. You can always refer to the instructions on this page whenever needed.