When And How To Change Spark Plugs In A Car

Replacing new spark plugs and taking a rest

When it comes to the components of your car, you can never be too sure about the condition of the parts unless you have an expert check them out.

One component that determines the functioning of the car engine is the spark plug.

This needs to be changed every once in a while whenever the existing one is noticed to be unable to work well in the car.

Here’s how to change your spark plugs in your car by following the following steps:

  1. Drape An Old Blanket Over The Car Fenders To Avoid Damaging The Car’s Paint
  2. Thoroughly Clean The Area Around The Spark Plug
  3. Remove The Spark Plug Wires In Order To Avoid Confusion
  4. Connect The Tools Of The Socket Well As You Prepare To Remove The Old Spark Plug
  5. Use The Spark Plug Tool To Correct Any Gap Available In The New Spark Plug
  6. Install The Spark Plug In The Hole Using Your Hand
  7. Connect The Plug Wire
  8. Clean The Area Thoroughly

As seen in the steps above, changing the spark plug in a car is a simple task that can be completed by just anyone.

All you have to do is to collect the required tools and you will be able to get the task completed.

You should be careful not to let dust and debris into the plug hole as this might cause complications in future.

Benefits Of Changing Spark Plugs

When spark plugs are used for long they are bound to develop deposit build-up and this will cause an unreliable supply of energy to the car.

Similarly, their gaps will widen and the combustion will be either erratic or ineffective.

You will need to replace your car’s park plugs to enjoy the following benefits:

  • An effective provision of combustion: This will be ensured with a new and top performing spark plug.
  • Improved fuel consumption: Old spark plugs lead to fuel inefficiency by a significant percentage.
  • To enjoy smooth ignition: If you have ever ignited a car with a good ignition then you understand the feeling. These are the stress free starts that you will be able to enjoy when you install a new spark plug in your car.
  • Safe for the environment: New spark plugs do not emit harmful emission to the immediate environment.

What Tools Should You Need To Replace Spark Plugs?

The following tools will be necessary when you want to change your car’s spark plugs. They will help with the process and avoid damaging the components.

1. Spark Plug Swivel Socket With Extension

This particular tool is designed to fit into the tightest of places. The fact that it takes less space enables it get the job done without damaging any other components.

2. Flexible Handle Ratchet

This will provide a good angle for the removal of the old spark plug from its position.

When assembled with its ratchet, it will be able to get the job done and you need to adjust the angle for a better functioning. It will make the work easier because of its usability.

3. Spark Plug Boot Puller Pliers

This will help avoid damage that is caused when you try to separate the spark plug boots from the plug itself.

When you pull it off directly, you might get it damaged. It will help you to gently separate the two while avoiding secondary damage.

4. Spark Plug Gap Gauge

This will help in verifying the gap in the new spark plug before connecting it. You need to verify the gap according to the specifications of the manufacturers.

This is because through the logistics of the new spark plug, the gap may be interfered with hence the need for gap correction before you install it into your car.

5. Torque Wrench

This will help with the torqueing of the spark plug before installing it into the car. It will help to prevent the possible damage of the engine.

You should avoid over-tightening it as this will damage the threads of the spark plug.

On the other hand, it should not be loose either. The torque wrench will ensure an appropriate fit is achieved.

6. Wire Loom Spacers

This tool is needed to prevent misfires that may damage the gas mileage or even destroy the ignition coil.

This is why the spark plugs need to be spaced appropriately and this is the tool for this task.

What Other Materials You May Want To Use

Apart from the above tools, there are those other materials that will ensure that little or no damaged is passed to the spark plugs.

1. Anti-Seize Lubricant

This is used and applied to the threads of the spark plugs while avoiding spilling it onto the electrodes or the porcelain.

It will be helpful to avoid a situation where the spark plug sticks to the cylinder head threads.

2. Spark Plug Wires

With time these two get damaged and this will cause arcing and misfiring that you do not actually want to deal with in your car.

When you do not give this attention, your car’s gas mileage will be interfered with and this will affect the ignition too.

3. Distributor Cap

The distributor cap is affected with centrifugal force that expels the ground-up carbon that is located in the inside of the cap. This then causes “carbon tracking” which leads to the misfiring of the plug.

Whenever you are changing your spark plugs, it is a good idea to replace the distributor cap.

This will help avoid costly repairs in future as the ignition and other components that might be affected with a spark plug in poor condition.

How Do You Remove And Install New Spark Plugs? {Let’s Find Out!}

You should know that removing and installing a new spark plug in the car engine is a simple task just like changing a punctured tire.

You just need to know the basic parts and assemble the required tools for the job.

You should then follow the procedure below as you observe some safety precautions and you will have installed the new spark plug successfully.

The Process Of Removing A Spark Plug

1. Drape An Old Blanket Over The Car Fenders To Avoid Damaging The Car’s Paint

After you have collected all the required tools and equipment, it is now time to remove the old faulty spark plugs.

You will fist need to cover the car’s paint to avoid marring it as you continue with the task.

When you are doing this task, you will have to lean over to reach the engine and this might interfere with the paint job. You can avoid this by covering it with an old cloth or an old blanket.

2. Thoroughly Clean The Area Around The Spark Plug

You should know that when you remove the old spark plug, the hole will be empty and debris and dirt will enter.

You do not want this to happen and thus the reason why cleaning the area before removing the current spark plug is advised.

This can be done using a compressed air to blow off the dirt or debris around the area.

You can even use a relevant cleaner or a degreaser for quality results. You should be safe to avoid the dirt and debris from entering either of your eyes.

3. Remove The Spark Plug Wires In Order To Avoid Confusion

If you are dealing with a spark plug that actually has wires, then you need to remove them one at a time.

Removing them in this order will avoid confusion as you will be noting what goes where.

It will be dangerous reconnecting the wires in a wrong order as this will cause development of complications.

For the coil-on-plug type, you can simply disconnect the coils and set them aside safely. When you are dealing with bolts, you need to be keen not to misplace even a single one.

4. Connect The Tools Of The Socket Well As You Prepare To Remove The Old Spark Plug

When it comes to the socket, you will need to connect the combinations of the extensions and the swivels.

This will help you fit the tool to the spark plug and help you with the task of removing it.

You can then remove it by turning the spark plug using the tool in a counter clockwise direction. You should turn it until the spark plug is removed from its position.

When the old spark plug is removed, you need to be careful not to knock any dirt or debris into the position of the spark plug.

The last thing you want to deal with is dirt entering the position of the spark plug.

5. Use The Spark Plug Tool To Correct Any Gap Available In The New Spark Plug

While some spark plugs are designed in a quality manner such that they are gapped when they are in the factory, this is not always the case for all of them.

Some might be gapped by the manufacturer but while being shipped they develop a gap. The gap might be small but it is always crucial.

You can obtain a spark plug gap tool and use it to correct the gap in the new spark plug. This will do the trick especially if you know how to work with the tool.

You can work it by opening and closing the tool while making the adjustments. You can check on the owner’s manual for better clarifications.

The Process Of Installing A Spark Plug

6. Install The Spark Plug In The Hole Using Your Hand

Once the gap has been corrected, you can now install the new spark plug using your hand.

Some brands of spark plugs are not treated with anti-seize, for them, you can rub a drop of anti-seize lubricant to the surface of the spark plug.

This will help prevent it from locking when affected by too much heat.

You can then gently start screwing the plug in a clockwise rotation while checking on the threads. The threads should be properly mated for the task to be done successfully.

You can then use the hand tools to tighten each and every plug to spec.

It is recommended, on a general situation, you should not give more than an additional quarter turn after the hand tightening part.

7. Connect The Plug Wire

After you have ensured that the spark plug has been well installed, you can reconnect the plug wires while ensuring that each of them is placed to the right part.

Some will require the insertion of the ignition coil.

For the task of the reattaching of the plug wire, you should twist slightly as you continue to push the boot downwards on the exposed tip of the plug.

You should do this until you hear and feel a firm click sound. This will indicate that the plug wires have been well connected.

For the purpose of proper heat dissipation, you should a drop of dielectric grease into the plug boot.

8. Clean The Area Thoroughly

Once you have ensured that the new spark plug has been well installed, it is time to clean the area around it thoroughly. This is for the same reason as indicated above.

After this, you should be satisfied with the work you have done as you will have completed the task. You can try it out to be sure if you have done the work successfully.

I also highly recommend you to watch this video:

How Often And When Should You Need To Replace Spark Plugs?

Generally, spark plugs need to be replaced after approximately 30000 miles.

They are amongst the most durable parts of the car as they do not need to be replaced as often as some of the other components.

For some cars, their spark plugs will be in good condition for several years as you use the car for your traveling.

However, some spark plus will be longer lasting than others.

This is because some manufacturers of spark plugs design their products to be highly durable and as such can go for many miles before they are in poor condition.

You may also notice that some cars will not need their spark plugs to be replaced quite often like in others.

What Are The Symptoms Of Bad Spark Plugs?

You can realize whether or not you will need to change the spark plug in your car if you notice any of the following signs:

  1. Fuel inefficiency: You might notice that your car consumes quite a lot of gas than before. This might be caused by many other factors such as a damaged engine or something. However, in some cases, the issue might lie with the spark plug.
    If you have an old spark plug in use, it will cause the car to be unable to receive the appropriate heat-generating spark that is needed at the right time.
  2. Poor performance: A poor spark plug will be unable to do its job while you are driving.
    This is seen when it is unable to work as well as it is needed to when you are accelerating or changing gears as you drive on the road. This will make the car move sluggishly and it will consume more fuel than normal.
  3. Poor start: A car with a spark plug in poor condition will be unable to start as it would normally.
  4. You will hear noises: Misfiring spark plugs may be noticed when you hear abnormal sounds that sound like rattling or “knock” noises.
    These sounds arise from the force of the pistons and the combustions not working as they are supposed to.
    Since the pistons are designed to travel at high speeds, when the spark plug misfires the unusual sounds are produced.

How Many Spark Plug Do You Need To Change?

The number of spark plugs that need to be changed depend solely on the type of car in question.

Some car engines might even use six spark plugs while some will use a total of twelve spark plugs.

How Long Does It Take To Change A Spark Plugs?

Replacing the spark plug will not take more than an hour provided you have the right tools for the task or that you follow the instructions provided in this article.

If you are a handy man, you can complete the task in less than half an hour.

What Happened If You Don’t Change Your Spark Plugs?

If you do not change your spark plug whenever it is time to, you risk damaging several other components of the car engine.

This is because the parts of the engine are connected, so when one part is faulty it will affect the normal function of the others.

Similarly, your car will consume a lot of gas than usual and will not work well as you drive.

Does Changing The Spark Plugs Make A Difference?

Yes, when the spark plug in a car is changed, you will notice a number of differences.

For one, the car will have a quick and smooth response when ignited.

You will also notice a more efficient fuel consumption rate and also all the unusual noises cause with the pistons will not be heard any more.

One significant difference you might notice with a newly installed spark plug is that the cold starting of the car will be improved.

While old spark plugs require a high voltage for creation of a strong spark that is needed for the starting of the car.

This might kill the battery even before you move a step with the car. However, this is not the case when you have a new spark plug installed on your car engine.

You will also prevent the development of a catalytic converter failure. This is caused when there is a misfire that arises from working with a spark plug in poor condition.

This creates an ugly and costly scene as there would be a lot of repairs needed before the car is able to function normally.

You are advised to replace the spark plug as soon as you can to avoid dealing with such a situation.

Can You Use 2 Different Brands Of Spark Plugs?

Yes, there is nothing wrong with using two different brands of spark plugs.

You can actually interchange the brands of the spark plugs without fearing that there will be complications that will develop in future.

You just have to ensure that the performance of the brand you are going for is optimum.

Do Spark Plugs Brands Matter?

Yes, the brand of the spark plug matters.

You want to go for the top quality ones as this would guarantee top performance. The inferior brands have little to offer and may actually not be useful for you.

You might have noticed that your car’s spark plug is damaged and needs to be replaced.

This is needed to be done as soon as possible to avoid your car from developing complications when you are using it.

If you can afford a top brand, then you should go for it. It will guarantee top performance as well as a being long lasting which is what you need to avoid spending too much on car spares.

The brand also matters when it comes to the model of car that you own.

Some brands of spark plugs are meant to perform better in some models of cars and you will notice when the same spark plug that works well in one car engine is unable to function well in another.


All in all, every car owner needs to maintain their car parts and this is the same for the spark plug.

You should regularly check on it and be on the lookout for signs that show it is damaged.

This will help avoid affecting the ignition and improve the efficiency of the fuel consumption.


1. Advance Auto Parts – https://shop.advanceautoparts.com/r/car-projects/how-to-change-spark-plugs
2. AutoZone – https://www.autozone.com/diy/spark-plugs/how-to-change-spark-plugs


Written by Kane Dan

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