What Is A SPARK PLUG? Learn About Cost, Location, Replacing etc.

We’re starting a series of short articles that each explain an essential part of a car.

Today, we begin with the Spark Plug.

What Is a Spark Plug On a Car?

A spark plug is an essential component of your car’s combustion engine. It creates a tiny but powerful electric spark that ignites the air-fuel mixture inside the engine cylinders. This ignition process produces the energy needed to power your vehicle.

When you turn the key in your car’s ignition or press the start button, the battery sends a high-voltage pulse to the ignition coil. This amplifies the voltage, which is then sent to the spark plug via the spark plug wire.

The high voltage allows the spark plug to create a spark that ignites the air-fuel mixture, pushing the piston downward to generate power for your engine.

Spark plugs come in various materials like copper, platinum, or iridium, each with its specific heat range and performance characteristics. It’s essential to choose the right spark plug for your engine to ensure optimal performance and avoid potential engine damage.

What Do Spark Plugs Look Like?

Spark plugs are the size of a finger and they have a spiral ridge at the one end – like you find on a screw, bolt, or nut.

Here’s a picture:

Car spark plugs

Spark plugs have a fairly simple design. They come in different sizes and designs based on the engine’s requirements.

Do All Cars Have Spark Plugs?

Gasoline-powered cars do have spark plugs, diesel vehicles don’t require them, and electric vehicles don’t use them either.

Spark plugs are a vital component of the design of a combustion engine.

Where Are Spark Plugs Located In a Car?

Spark plugs are attached to the engine cylinders, and you’ll find them connected through ignition wires or coil-on-plug units. Different cars have varying numbers of cylinders, so you might find four, six, or eight spark plugs, depending on your vehicle.

Accessing the spark plugs might be a bit difficult, depending on your car’s design. In some vehicles, you can easily see and reach the spark plugs, while others may require you to remove some parts, like the air intake or even the entire engine cover, to get proper access. It’s always a good idea to consult your vehicle’s owner manual for specific guidance on locating the spark plugs and any necessary steps to access them.

Once you’ve reached the spark plugs, take a look at their arrangement. They’re usually positioned along either side of the engine, in a row. In V-shaped engines, you’ll find them divided between the two banks of cylinders. In inline engines, you’ll find them in a single row on one side or the top of the engine.

Remember, before trying to access or inspect the spark plugs, ensure that the engine is cool, as it can get extremely hot during operation.

How Long Do Spark Plugs Last?

Spark plugs normally last anywhere from 30,000 to 100,000 miles, depending on the type and quality of the spark plug.

For instance, copper spark plugs typically need to be replaced more frequently, around every 30,000 miles. On the other hand, iridium and platinum spark plugs are more durable and can often last up to 100,000 miles.

Now, if your car sits idle for extended periods, it’s a good idea to consider the age of your spark plugs as well. In such cases, your spark plugs should be replaced every 5 to 7 years.

Remember to consult your vehicle’s manual to find specific recommendations on spark plug replacement intervals for your make and model.

How Much Do Spark Plugs Cost?

When you need to purchase new spark plugs, you’ll find that they can range in price depending on the brand and material. Typically, you can expect to pay anywhere from $2 to $15 per spark plug.

Expect to spend between $30 to $60 for a set of four spark plugs. If you need to replace all eight spark plugs in a V8 engine, the cost can be anywhere from $60 to $120. Keep in mind, these are just the costs for the parts themselves.

Here’s a quick breakdown of the general price range:

Spark Plug Type Price Range
Copper $2 – $5
Platinum $5 – $10
Iridium $8 – $15

How Much Does It Cost To Replace Spark Plugs?

Now, if you’re planning on having a professional mechanic do the job for you, the labor costs can add an additional $40 to $150 depending on your vehicle’s make, model, and specific labor rates in your area.

Just to give you a nice overview, here’s a breakdown of the possible costs involved:

  • Spark plugs themselves: $60 to $120 (depending on the number of plugs)
  • Labor cost at a mechanic: $40 to $150

While it’s definitely possible to replace your own spark plugs, it might be a good idea to let an experienced mechanic handle the job if you’re uncomfortable or unsure about doing it yourself.

What Happens When Spark Plugs Break?

When your spark plugs break, you may notice that your car struggles to accelerate, has a rough idle, or experiences poor fuel efficiency.

Trying to drive with faulty spark plugs can lead to even more problems. In some cases, it may cause misfires, which can damage your engine and its components, such as the catalytic converter. Not to mention, the unburned fuel that results from misfires can increase harmful emissions, and it’s really not good for the environment.

Now, you might wonder if it’s possible to drive without spark plugs. In simple terms, no, you cannot. Spark plugs play a vital role in igniting the air-fuel mixture within the combustion chamber, which is essential for your engine to run. Without them, your car simply won’t start, and you’ll be left stranded.

Can You Replace Spark Plugs Yourself?

Yes, you can definitely replace spark plugs yourself! It’s not as difficult as you may think.

First, gather the necessary tools such as a ratchet, socket, extension, spark plug gapper, a small tube of di-electric grease, and of course, the new spark plugs. Make sure to consult your vehicle’s owner’s manual for the correct spark plug specifications.

Before you begin, let your engine cool down to avoid burns. In a cold engine, locate the spark plug wires or coils; these are usually found on the top or side of the engine, following a row of plugs. Carefully remove the spark plug wire or coil from the plug by pulling on the boot, not the wire itself.

Next, use a spark plug socket and ratchet to remove the old plug by turning it counterclockwise. Once removed, inspect the old spark plug for signs of wear, such as oil deposits or excessive charring.

Take your new spark plug, and using the gapper, adjust the gap between the center and ground electrode to the specifications listed in your owner’s manual. When the gap is set correctly, you’re ready to install the new plug.

Carefully thread the new spark plug into the engine by hand, ensuring it goes in smoothly and doesn’t cross-thread. Once hand-tightened, use the ratchet and socket to tighten the plug an additional 1/4 to 1/2 turn, being cautious not to overtighten.

Add a small amount of di-electric grease inside the spark plug boot and reattach the spark plug wire or coil. Repeat this process for each spark plug, working on one at a time to avoid mixing up the wires or coils.

And that’s it! You’ve successfully replaced your spark plugs. Remember to periodically check and replace your plugs as needed, according to your vehicle’s maintenance schedule.

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