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How Often To Change Spark Plugs? All That You Need To Know! 

How Often To Change Spark Plugs

Spark plugs are very small components, but they have a vital role in your car. Without perfectly working spark plugs, your vehicle will not be able to start. Therefore, it's very crucial to familiarize yourself with how often to change spark plugs.

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Like any other components in your car, the spark plugs can go bad and require maintenance. Luckily, there are many signs of bad spark plugs that you can follow and try to monitor. If you notice any of these signs, you must replace the spark plugs immediately. Failing to replace the spark plugs on time prevents you from driving your vehicle properly.

The purpose of this article is to help you understand how often to change spark plugs. Also, the article answers a couple of additional questions related to our vehicle's spark plugs. 

What is the spark plug, in how does it work? 


The spark plug is a small electrical device located inside your engine's cylinder. This device is responsible for igniting the gasoline inside the combustion system to start the explosion.

There are two types of engine’s: spark ignition engines and compression ignition engines when starting the combustion process.

This spark ignition engine requires a certain spark at the right time to get the combustion started. However, the compression ignition engine requires compressing the air gas mature before starting the ignition process. 

How often to change spark plugs? 


Like any other vehicle component, spark plugs are not designed to last forever. At some point in time, you must replace a bad spark plug.

According to automobile experts, most spark plugs need to be replaced between 30,000 to 90,000 miles.


However, this timeline can differ between vehicles and depending on your driving style. The best guidance for you when it comes to replacing the spark plug is to monitor any bad spark plug signs.

In other words, your spark plug will tell you that it's going to get bad soon before it does. Therefore, it's recommended that you keep an eye for signs of a bad spark plug to best guide yourself whether you need to replace it before the 30,000 miles. 

What are the different signs of a bad spark plug? 


As we mentioned earlier, your spark plug needs to be replaced between 30,000 and 90,000 miles. However, you might need to replace the spark plug if you see or notice any of the following signs: 

  • You will notice a significant reduction in your gas mileage 


The first and most important symptom of a bad spark plug is your vehicle's reduction in fuel economy. If this work plug is clogged and it does not provide the spark at the right time, your engine will request additional fuel from the fuel pump, assuming that the problem is due to the insufficient fuel supply.

As the pump tries to send additional fuel to the engine, your vehicle will not produce the required energy at the specific amount of fuel. In other words, you will need to visit the gas station more frequently. 

  • You might experience issues when you attempt to accelerate 


How will the spark plug affect your car's acceleration? Great question! When the spark plug is clogged, your vehicle might act sluggishly, and you will notice this, especially if you try to accelerate. The spark plug is not providing the correct spark timing, which will result in a lag in the car's response to acceleration.  

  • Starting your vehicle can be a little hard 


Problems with starting your vehicle can be due to many different culprits, including your battery, your starter, and others.


While the spark plug might not be the most common issue resulting in starting your vehicle, it might be the culprit. Your best approach to confirm here is to contact your professional mechanic and have him inspect the car to identify the root problem. 

  • You might experience an engine misfire 


Similar to starting problems, engine misfire can happen due to many reasons. One of those reasons could be a bad or faulty spark plug. Again, if you've experienced an issue with an engine misfire, your professional mechanic would be the best person to confirm the problem and make sure it's the spark plug, not anything else. 

  • Lastly, you might have to deal with issues with rough idling 


If the spark plug is working perfectly fine, the engine will behave smooth, and you will not hear any weird issues when idling. However, if the spark plug is partially clogged or has some problems, the engine will start making weird sounds, and you will experience rough idling. 

Most mentioned symptoms are not directly related to the spark plug because all of these symptoms might be associated with other faulty components in your vehicle.

The best option for you is whenever you notice any of the mentioned symptoms. You must take your vehicle to a professional mechanic and do a quick inspection. after the inspection, the mechanic will determine whether your bad spark plugs a different component. Whatever the component was or whatever the culprit was, you must take care of it as soon as possible to reduce the link's potential was complicated repairs that require a lot of money. 

How much does a spark plug replacement cost? 


When it comes to replacing the spark plug, you don't need to expect any money. In other words, replacing the spark plug itself is not expensive. However, the maintenance cost can be a little high and add a lot to the bill.

In general, you could get a new spark plug for between $16.00 to $100, depending on your car's make, model, and year.

When it comes to the maintenance costs, it differs significantly depending on the repair shop that you select. For example, if you decided to go to a small repair shop, you don't have to expect much money compared to a professional dealership.

In general, labor costs for replacing a spark plug range from $40 to $150.

While replacing the spark plug might not be very costly, ignoring and driving with a bad spark plug can introduce additional problems resulting in significant repair costs.

For example, a bad spark plug can introduce engine misfires and additional issues with the vehicle's combustion system, resulting in engine failure in severe cases.

Therefore, never ignore about spark plug and wait on it for a long time. Think about the amount of time and effort you will need to deal with a faulty and a damaged engine.  

How to replace your vehicle's spark plug without a mechanic? 


As we mentioned earlier, replacing the spark plug does not cost a lot if you go to a small repair shop. You can even cut all maintenance costs by replacing your spark plug yourself. Here's all you need to do to replace your vehicle spark plug by yourself: 

  • Prepare the required tools and material 

It's important to bring the required tools and materials before starting the replacement process. This way, you save yourself much time and effort looking for different tools in the middle of the year placement.

To replace your vehicle spark plug, you need the following tools: a gap gauge, a torque wrench, a swivel socket, a spark plugs wire puller, a socket ratchet set, rags, and needle-nose pliers. 

You will also need a new spark plug or spark plugs, depending on how many faulty spark plugs you have in your combustion system. Furthermore, you need to prepare an anti-seize compound. 

  • Remove your engine's plastic cover 

To get started, you need to locate your vehicle's spark plugs, usually located in the engine. If you have a hard time locating your car's spark plug, you can always refer to your vehicle's owner's manual.

If you don't have a copy of the manual, you can obtain a hard copy from your professional mechanic or download a soft copy from the Internet.

Once you open the plastic cover, it's important to use an air cleaner to clean any dirt around the engine and make sure you're starting with a clean area. This way, you prevent any dippers and dirt from making their way to the engine's area.

  • Take out the ignition coil 

Once you opened the engine's cover, locate the ignition coil and disconnected it by pulling it out. If you have a hard time disconnecting, pay attention. You might need to use a spark plug wire puller to make it much simpler to take it out.

  • Take the plug out by unscrewing it 

Again, make sure to clean any dirt by blowing it away before unscrewing the plug. Use your socket to rotate and loosen the plug. The rotation must be done counterclockwise. 

  • Make sure to gap the spark plug before installing it


Using the manufacturer specifications, ensure that you gapped all plugs before installing them. 

  • Insert your new spark plug in the correct location 


Once you finished gapping the spark plug correctly and according to the specifications, it's time to install the new one.

Use a torque wrench and make sure to tighten the spark properly. You don't need to overtighten it, and you don't also need to keep it loose. Refer to the manufacturer's specifications to get the right amount of tightening required for installing a spark plug. 

Finally, make sure to loop the spark plug boot 

Automotive experts and professional mechanics recommend applying a thin coating of some grease around the spark plug boot before installing it to the coil. This grease helps prevent another misfire from happening and occurring in the future. 

Once you apply the grace, you can go ahead and install the ignition coil and the air cleaner. You're all set! You can go ahead and give your vehicle a test start. You will be surprised by the different experiences you'll have once installing the new spark plug! 

How can I tell the difference when installing a new spark plug? 


The spark plug is very important to significantly affect your driving experience if you have a bad spark plug. Immediately after your mechanic replaces the old spark plug, you will notice significant improvements in your driving experience and your vehicle's behavior.

Some of these differences include:

  • Your vehicle will work at the highest efficiency, and you will notice a significant improvement in the fuel economy. When the spark plug sends the spark at the right time, the engine performs as it was designed for. In other words, your engine will burn the required amount of fuel at the right time and generate the required energy needed to accelerate. Therefore, your engine doesn't have to suffer or stress the pump to send additional fuel, which could cause a reduction in fuel economy, as we mentioned before.
  • You will not experience any problems with starting your vehicle. The starting process will be very smooth and no more sluggish driving.
  • Overall, when you're driving with a good spark plug, you're helping the environment by reducing the number of harmful emissions. A good spark plug can help reduce fuel consumption and maintain the right proportion between fuel and air, which results in the least amount of harmful gases possible. 



Spark plugs are very small; however, they have a very important role in your car, and without good spark plugs, you might not be able to start your vehicle in difficult situations. 

It's important to replace the spark plug when needed. Most automotive experts suggest that you need to replace the spark plug between 30,000 miles and 90,000 miles. However, the number can be much different depending on your driving situation, the type of fuel that you’re using, and your vehicles' performance. 

In other words, you should keep an eye for symptoms of the bad spark plug in case you need to replace it before the 30,000 miles.

This article summarized the different symptoms of that spark plug along with the expected repair costs for changing your bad spark plug.  

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