What Are the Symptoms of Bad Spark Plugs and How Often to Replace?

by Chris Lewis.

Spark plugs are an essential part of vehicles, which determines the performance of the vehicle more significantly than you can imagine. And that is why you should not take the importance of these devices lightly.

You should pay attention to these from time to time and change them when you deem necessary. But for that, you will need to be aware of when they need to be replaced, and that's what we will inform you about in this article.

Here, we will be answering your question - what are the symptoms of bad spark plugs, and how often to replace them?

Once you know all the details regarding this issue, you will be able to change them when necessary without causing any damage.

So stay with us to enlighten yourself with all the information that you need regarding this.

What Are Spark Plugs?

What Are Spark Plugs?
What Are Spark Plugs?

A spark plug is a device that is primarily known for delivering electric current to the combustion chamber of an engine that is spark-ignited. These devices deliver the current from an ignition chamber itself.

The end result of this process is that it ignites the compressed fuel and air mixture through an electric spark while maintaining the combustion pressure within the engine so that it operates properly.

You need to consider its wrench size, heat range, and number along with torque when getting one.

There are also a few things that you need to keep in mind while using it; for instance, the frequency at which it should be changed and when.

What Are the Symptoms of Bad Spark Plugs?

What Are the Symptoms of Bad Spark Plugs?
What Are the Symptoms of Bad Spark Plugs?

One of the crucial aspects of using spark plugs is recognizing the symptoms of a bad one. Often, people tend to neglect the obvious signs, which leads to unwanted results.

For instance, if you don't replace the spark plugs, they will deteriorate over time. As a result, the combustion in the engine remains incomplete and provides chaotic consequences.

Such as, the engine will lose its power, or in the worst-case scenario, not run at all. Therefore, recognizing the symptoms and replacing them on time is necessary. That is why we will be discussing all the signs in this part of the article.

  • The Vehicle Is Difficult to Start

Usually, when a vehicle struggles to start, the battery is blamed without looking into the other components.

However, a clogged spark plug may be at fault as well, and this is usually the first symptom of malfunctioning spark plugs. Hence, don't turn your focus to other issues and make sure the spark plugs are alright before anything else.

  • Reduced Fuel Economy

Now, spark plugs are used for proper combustion in the engine; and if they go bad, then they will surely fail to complete the combustion at times.

If that happens, the fuel will struggle to burn properly, which will only reduce fuel economy - that is, you will need to buy more fuel. If that happens, then make sure to replace the bad spark plug before it incurs more costs.

  • Engine Misfires

An engine can misfire due to a lot of issues related to the vehicle. It can also signify the damage of certain engine parts that you should look out for.

However, it is also a signal of a spark plug malfunctioning, which you shouldn't overlook under any circumstances. Make sure to check all the spark plugs and replace them before it causes more damage.

  • Vehicle Struggles to Accelerate

A deteriorated spark plug will not complete the combustion in the engine. As a result, your engine may face a loss of power, which may hinder its ability to provide the acceleration that your vehicle needs.

Hence, if you see that your vehicle is struggling to accelerate even with several attempts, then you will need to take that as a sign of your spark plugs going bad and check them immediately.

  • The Engine Idle Gets Rough

Another sign of spark plug malfunctioning is when the engine idle gets rough. The obvious way to know that is when the engine starts rattling or knocking.

This can signal other issues related to the engine as well. But that doesn't mean you should miss out on checking the spark plugs. Check them right away for no delay.

  • Check Engine Light Comes on Frequently

If you are familiar enough with an engine, then you are surely aware of the fact that the engine has a way of letting you know about its issues- that is, by making its light come on when a problem arises.

Hence, if a spark plug in the engine goes bad by any chance, the engine light will come on frequently. This should be enough of a signal for you to check the spark plugs.

  • The Engine Is Louder than Usual

A healthy and fresh engine with equally strong parts will not generate loud noises. Hence, no matter how many cylinders your engine contains, you will be able to notice if any spark plug starts malfunctioning.

The engine will generate a noise that will be close to rattling, and hence the difference will not be difficult for you to notice. Although this can be a signal for other issues as well, do check your spark plugs.

  • The Frequency of Spark Plug Replacement

How frequently you will need to replace the spark plugs of your vehicle depends on some factors. But always remember to get it done before it's too late because it can cause some severe damage.

So in this section of the article, we will talk about the frequency of their replacement.

How Many Miles Should You Go?

How Many Miles Should You Go?
How Many Miles Should You Go?

If you have average spark plugs for your vehicle, then you can expect it to function properly for about 25,000-30,000 miles. Most spark plugs are capable of lasting at least this long.

However, if you have expensive spark plugs that come from a renowned brand, then you can expect it to last for 90,000-100,000 miles at least. And no, we are not exaggerating!

So the lifespan of your spark plugs depends on the amount you have spent on them and how reliable their brand really is.

Just Pay Attention to the Signs!

Even though we have discussed how certain spark plugs in different price ranges can last forgiven miles, there's no guarantee that they will function properly for that number of miles.

That is why you need to pay attention to the signs that your vehicle and your engine send you. A malfunctioning spark plug can disrupt the operation of a vehicle in multiple ways, so pay attention to it.

If it is difficult for you to detect the issues, then you can also have a thorough check-up of your vehicle and its parts from time to time.

Final Words for Spark Plug Buyers

An important step of taking care of your vehicle is knowing its parts properly and taking care of those as well. One of those parts is a spark plug, and you should know the ins and outs of it too.

So, after you have gotten the answer to what are the symptoms of bad spark plugs and how often to replace them in this article, you will be able to change them accordingly.

About Chris Lewis.

Chris Lewis is a passionate individual with a deep affinity for the world of automobiles. From a tender age, his fascination with cars was nurtured by his father, a seasoned mechanic based in the vibrant city of San Francisco. Growing up under the watchful guidance of his skilled father, Chris developed an early aptitude for all things automotive.

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