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How Much Does A Spark Plug Replacement Cost? (+5 FAQs)

January 24, 2022

Changing spark plugs can be relatively inexpensive, and new plugs do not need as much maintenance as other car parts. 

However, when it’s time to replace them, how much does a spark plug replacement cost
And what’s the right solution for replacing spark plugs?

In this article, we’ll answer these questions and some other frequently asked questions, including how often you should replace your worn spark plugs, and whether you should replace them in pairs

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Let’s begin! 

How Much Does A Spark Plug Replacement Cost

Spark plugs are a small but integral part of your internal combustion engine. They’re responsible for getting electrical energy from the ignition coil pack to burn the air fuel mixture. 

While they don’t require much maintenance, you do need to change them after certain intervals. The cost for a spark plug replacement primarily depends on two factors:

1. Cost Of Spark Plugs

This price is largely driven by the type of spark plugs you’re going to be using. Whether you buy copper, platinum, or iridium spark plugs, you can expect to pay anywhere from $5-$50 per piece. 

To give you a fair idea here’s how much different types of spark plugs cost: 

Your mechanic should be able to determine the best spark plugs for your car.

2. Labor Charges

Labor charges are the fees you pay to your mechanic for your repairs. For a faulty spark plug replacement, you can expect to pay anywhere from $40-$350.

These charges will also vary from engine to engine. 

For example, a repair shop may charge $60-$140 for a four-cylinder engine. For some V6 engines (6-cylinder), the intake manifold has to be taken out to access the bad spark plug, taking the labor costs as high as $260-$320 for the car. 

In total, a spark plug replacement can cost you anywhere from $100-$250 on the low end, and $250-$500 on the high end (usually for V6 engines).

Now that we have that out of the way, let’s take a look at other queries about changing spark plugs, and their answers.

5 Spark Plug Replacement FAQs

Here’s what you should know about replacing spark plugs.

1. Should I Replace All Spark Plugs? 

Ideally, yes. 
A spark plug replacement is done to ensure that worn spark plugs do not cause a misfire, engine surging, or problems with ignition coil packs. Even the power steering can be affected by power loss due to spark plug issues.

If you replace one bad spark plug at a time, each spark plug will end up being on different replacement cycles. As a result, you’re spending more time and effort changing spark plugs every time you encounter a spark plug problem.

Another reason why spark plugs need to be replaced as a set is that you need your car’s spark plugs to be on parallel levels of performance. 

For example, if you have a faulty spark plug in two out of four cylinders in a V4 engine while the others are relatively new, it would put the engine out of sync.

2. Do I Need To Replace The Spark Plug Wire Too?

Usually, yes. 
Spark plug wires often get chipped or cracked with regular engine wear and tear. 

A good rule of thumb is to replace your spark plug wire every time you change a faulty spark plug. Old spark plug wires are obviously more prone to damage and wear. 

It’s also a good idea to have your fuel filter, oxygen sensor, coil pack, etc replaced around the same time. An old air filter can foul your new spark plug, cause rough idle, engine damage, and may trigger the check engine light. 

Applying dielectric grease on spark plug threads helps prevent the plugs from getting stuck to the boot when removing them next time. Make sure to keep the dielectric grease off any metal terminals, as it’s an insulator.

Note: A spark plug socket with a torque wrench is useful while handling a new spark plug. Along with dielectric grease, a spark plug socket can help appropriately install the new plug, or remove an old spark plug.

3. How Often Should I Replace My Car’s Spark Plugs?

It depends. Spark plug replacement intervals are determined by the type of spark plugs you’re using and how you maintain them. 

Conventional spark plugs have a changing interval of 30,000-40,000 miles while iridium spark plugs can last over 60,000 miles. Extended-life spark plugs need a new spark plug replacement every 100,000-120,000 miles. 

Regular inspection and spark plug changes at proper intervals will help prevent spark plug-related issues. These could include, but aren’t limited to, rough idle, check engine light turning on, poor fuel economy, engine misfire, or odd noises from the combustion chamber. 

Note: If you ever find an oily fluid on your spark plug electrodes, it’s due to a valve stem or valve seal leak. It could also be unburned fuel that flooded the engine during a failed cold-start. In this case, consult a mechanic. 

4. What Happens If I Don’t Change My Car’s Spark Plugs?

Over time, worn spark plugs can start affecting your combustion chamber and catalytic converter, eventually causing engine damage. 

The electrical energy from the ignition coil deposits on the spark plug electrodes, instead of jumping across and igniting the air fuel mixture in the combustion chamber. As a result, you may experience spark plug fouling, engine misfire, or your car may stop running altogether. 

An old spark plug will also lead to inefficient fuel consumption and fuel economy, and possibly cause trouble with your power steering. So it’s best to regularly change your spark plugs, wires, fuel filter, and other sensors.

5. What’s A Convenient Solution For Spark Plug Replacement?

A spark plug replacement can be pretty easy to DIY for someone with good mechanical knowledge. But in case you’re new to it or do not have the right tools, you can always reach out for help!

If you’re looking for a reliable mechanic for replacing spark plugs or another auto repair (like a dirty fuel filter, lit check engine light, or brake fluid leak) look no further than RepairSmith

RepairSmith is a mobile auto repair and maintenance solution with a range of car repair services. Here’s why we make a good fit for your car: 

Fill out this form to get a spark plug replacement cost estimate! 

Final Thoughts

The cost of your spark plug replacement depends on the type of spark plugs you use and your car’s engine requirements.

A spark plug replacement is usually a quick and easy procedure. A bad spark plug can lead to other engine problems like misfiring, poor fuel economy, and rough idling — so the more you prolong it,  the more likely it’ll lead to costly repairs.

If you ever decide to DIY your spark plug replacement, make sure you use the right tools. And if you need any help with it, you can always reach out to RepairSmith

RepairSmith can take care of all your car maintenance and auto repair needs. The best part? We come to you.

Contact us today to schedule an appointment with one of our expert technicians.