If you’re talking about getting a tune-up, chances are what you really mean is you’re changing spark plugs. Since the combustion engine was invented, these small fuel-air igniters have required routine maintenance. The electrodes wear out, as can be expected after a spark bridges the gap millions of times in thousands of hours of runtime.
However, prices don’t remain static. Where changing the spark plugs used to be a few dollars, it’s a bigger job that costs more on today’s vehicles. You can expect to pay between $3 and $20 per spark plug, although some unique models can range even higher. And when you need anywhere between four and 16 spark plugs depending on what you drive, there’s a chasm in what you can expect for pricing.
Here’s what spark plugs cost whether you do the job yourself or have a professional mechanic take care of it.
What are spark plugs, and why do I need to replace them?
Spark plugs supply the ignition source inside the piston of a gas-powered car. The spark happens up to thousands of times per minute. The tip of the spark plug is inside the cylinder of the car, and it is exposed to incredible forces that want to pit and degrade the business end.
Iridium and other exotic materials are now used to create the tips of the plugs so that they can last much, much longer than older spark plugs. Despite the longevity of modern plugs, they do eventually need to be replaced because they suffer degradation in normal use.
Symptoms of bad spark plugs
It’s best practice to change your spark plugs as often as the manufacturer recommends. That’s because when spark plugs fail, they can impact your engine function and could even leave you stranded. Still, if you don’t know when your vehicle’s spark plugs were last replaced, you might need to know some of the signs of bad spark plugs, including:
- Trouble turning over the engine
- Less engine power (which you might notice during acceleration or when traveling uphill)
- Reduced fuel economy, which could have you visiting the gas pump more often
- Engine misfires, which can feel like a jerking motion
- Check engine light, which comes on due to engine misfires
- Maintenance light, which may come on in newer cars when you need new spark plugs
It’s best not to put off changing your spark plugs. If a spark plug isn’t working properly, it leaves unburned fuel in the engine. Over time, that can damage your catalytic converter, which can cost thousands of dollars to replace.
Spark Plug Replacement Cost
On average, a spark plug replacement at a mechanic will cost between $115 and $200. The replacement cost includes both the price of the parts and the mechanic’s hourly rate. The mechanic will read the spark plugs, obtain replacement parts, and then remove and replace the plugs.
- Cost of parts: Spark plugs cost between $5 and $20 each, depending on the type of plug needed. Since you need as many plugs as there are cylinders in your engine, that means you’re looking at four to eight plugs, or anywhere between $20 and $160.
- Cost of labor: This is not a particularly labored procedure, so expect to pay for one or two hours of labor at approximately $30 per hour. Note that labor costs change dramatically from one zip code to the next.
There are two components to spark plug replacement cost: parts and labor. Spark plugs vary depending on the vehicle, but more so on the type of technology, they use for the center electrode’s core.
Here are the different types and a range of prices for each:
- Copper spark plugs are the most common and cost-effective with the majority under $4 per spark plug.
- Platinum spark plugs are more conductive, and most options are under $6 each.
- Double Platinum spark plugs use platinum for both the center and ground electrodes. They’re more expensive, ranging from around $5 to $20 per spark plug.
- Iridium provides a more dependable spark, and the price ranges from about $8 to $30 each.
- Double Iridium requires less energy, and they’re a good price point at around $8 to $15 each.
- Ruthenium spark plugs are longer lasting and burn more completely, and command around $15 to $209 each.
Related Posts: 7 Symptoms Of Bad Spark Plugs and How To Read It!
How Much Does It Cost To Replace A Spark Plug Yourself?
If you drive a compact car with a four-cylinder engine, an average set of platinum spark plugs will cost you about $32 or so. A six-cylinder will cost around $48, and a V8 will be around $64 for the parts alone. The exception is for unique models like the 5.7L HEMI engine from Stellantis. With two spark plugs per cylinder, you can expect to pay around $130 in parts alone.
How Much Does It Cost For A Professional Spark Plug Replacement?
If it’s a task you aren’t comfortable doing on your own, spark plug replacement costs at a repair shop will have labor costs higher than the parts. For instance, a set of four spark plugs in a compact car will likely be around $50 to $80 to install.
Some vehicles need an intake plenum or other parts removed to access the spark plugs, and the price goes up commensurately.
How Often Do I Need To Change My Spark Plugs?
In the past, experts recommended changing spark plugs every 30,000 miles or so. With today’s extended-life spark plugs, life expectancy can go as high as 100,000 miles.
Checking and replacing the spark plugs is usually part of your vehicle’s routine service interval. Rarely do you need to make an appointment just for the spark plugs.
Consult your Owner’s Manual for more details.
Should I Replace all Spark Plugs?
Ideally, yes. A spark plug replacement is done to ensure that worn spark plugs do not cause an engine misfire or problems with ignition coil packs. Even the power steering can be affected by power loss due to spark plug issues.
Regardless of type — whether copper, iridium, or platinum spark plugs, if you replace one failing spark plug at a time, each spark plug will end up on different replacement cycles. As a result, you’ll spend more time and effort changing spark plugs whenever you encounter a 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 your four-cylinder engine while the others are relatively new, it will put the car’s engine out of sync.
Note: Other parts, like the ignition coil, can also cause car troubles that might look like a spark plug issue. So, it’s best to get your car checked out by a professional before you replace your spark plugs.
Do I need to replace the spark plug wire?
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. Failing 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 a rough idle or engine misfire, affect fuel efficiency, and may trigger the check engine light.
Applying dielectric grease on spark plug threads helps prevent the plug 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.
Summary
Spark plugs play an essential role by providing the electrical bolts needed to burn the fuel/air mixture to turn the engine and make the vehicle move. Continuing to push a vehicle engine with worn-out spark plugs negatively affects the combustion chamber and the catalytic converter, eventually leading to engine damage.
Therefore, they must always be replaced at the recommended mileage intervals or immediately when there are signs of faultiness. Depending on your vehicle, expect to spend at least $100 or, at most, $500 for spark plug replacement.