If you notice poor fuel economy and weak acceleration, chances are your spark plugs are waving the white flag.
These tiny heroes ignite the fuel-air mixture that powers your engine. But once they wear out, replacing them is usually the best solution.
Wondering how much a new set of spark plugs will cost you?
Then, let’s explore the spark plug replacement cost in detail and see how it differs for each type. We’ll also learn how replacing the spark plugs on time can save your car from severe engine damage.
This Article Contains:
- How Much Does a Spark Plug Replacement Cost?
- Is It Worth Replacing a Bad Spark Plug?
- 7 Urgent Signs You Need a New Spark
- How Long Do Spark Plugs Last?
- 3 FAQs on Spark Plugs
How Much Does a Spark Plug Replacement Cost?
Here’s a rough estimate of your expenses so you’ll know what to expect when replacing worn-out spark plugs.
A. Range
Most automotive mechanics recommend replacing all the spark plugs at once for even performance. So, the average cost for replacing a spark plug set is around $50 and $750. This includes the labor cost of $40 to $350 and the price of spark plugs.
Now, spark plug prices depend on their material. Let’s have a quick look at the cost of different types of spark plugs:
- Copper spark plugs (or standard spark plugs): $2 to $10 per piece
- Silver spark plugs: About $5 per piece
- Platinum spark plugs: Approximately $10 per piece
- Double platinum spark plugs: About $20 per piece
- Iridium spark plugs: Around $20 to $100 per piece
B. Factors Affecting Cost
The final estimate for the replacement service can also vary depending on your vehicle make and model and the local labor rates.
Some other factors that can impact your repair cost are:
- Number of plugs: The more cylinders your engine has, the higher your spark plug replacement cost will be. For example, the Honda Civic has a four-cylinder engine with one spark plug per cylinder, so you only need to replace 4 spark plugs.
Some high-performance cars may also feature two spark plugs per cylinder, like the Mercedes-Benz M112. It has a six-cylinder engine with two plugs per cylinder, meaning you’ll have to swap out 12 spark plugs. This can drive up your replacement costs. - Spark plug location: Spark plugs in some cars are easier to access, while they aren’t in other vehicles, increasing the labor costs. For instance, in four-cylinder engine cars, spark plugs are on top of the engine, which are easy to replace. Whereas, in V6 and V8 engines, the spark plugs are on each side of the engine compartment, making them difficult to reach and often driving up labor costs.
- Additional repairs: Your mechanic will inspect and replace other parts, such as a bad fuel filter and ignition coil, which can add to your total bill. For instance, a fuel filter replacement will cost you $190 to $280 more, while swapping out the ignition coils can be around $85 to $470.
- Local repair shop plans: Some auto repair shops or dealerships may offer packages that include spark plug replacement and additional repairs of other parts, like the ignition coil pack, filters, or pump. You can choose the ideal plan that benefits your car and helps you save money.
Is It Worth Replacing a Bad Spark Plug?
Absolutely, yes!
Spark plugs are vital components of the ignition system. Once they wear out, your engine will misfire and idle roughly, resulting in poor fuel efficiency.
An engine misfire is especially damaging because it can cause incomplete combustion, where fuel isn’t fully burned. This happens when worn spark plugs fail to ignite the air-fuel mixture efficiently.
The unburned fuel can slowly harm other components, such as the oxygen sensor, coils, and engine cylinder. As multiple parts start failing, it’ll result in severe engine damage and a high repair cost.
So, when you hear your bad spark plugs ringing the warning bells, don’t ignore them.
7 Urgent Signs You Need a New Spark Plug
Here are some symptoms you’ll notice when you have a failing old spark plug:
- An illuminated maintenance or Check Engine Light
- Starting trouble
- The smell of unburned fuel due to incomplete combustion
- Rough idling
- Slow acceleration
- Engine misfire
- Low fuel efficiency
How Long Do Spark Plugs Last?
The lifespan of spark plugs depends on their material type. Here’s a general guideline:
- Copper spark plugs (or standard spark plugs): Last up to 10,000 to 20,000 miles
- Silver spark plugs: Last up to 20,000 miles
- Platinum spark plugs: Last up to 60,000 miles
- Double platinum spark plugs: Last up to 100,000 miles
- Iridium spark plugs: Last up to 100,000 to 120,000 miles
However, your spark plugs can wear out faster if:
- You drive aggressively and take short trips, which strains the spark plugs and wears them out fast.
- You add poor-quality fuel due to which contaminants accumulate on the plugs’ electrodes, deteriorating them slowly.
- You don’t replace the fuel or air filter as per the maintenance schedule, resulting in an improper air-fuel mixture.
- You drive in cold regions where spark plugs get fuel-soaked after failed starts or humid places where moisture dampens the plugs’ electrodes.
3 FAQs on Spark Plugs
Check out these common questions about spark plugs.
1. 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. So, a good rule of thumb is to replace your spark plug wire every time you change an old spark plug.
2. Do Electric Cars Have a Spark Plug?
No, electric vehicles don’t need a spark plug.
Gasoline-powered cars use spark plugs to burn the air-fuel mixture in the combustion chamber. Meanwhile, electric cars, like the Honda Prologue, Nissan Ariya, and Toyota bZ4X, rely on the battery pack, motor controller, and electric motor to run the vehicle.
3. Should You Replace a Faulty Spark Plug Yourself?
Ideally, you shouldn’t.
The location of spark plugs varies between cars. To replace the worn-out spark plugs, you’ll need tools such as a spark plug socket and a torque wrench, along with some technical know-how.
Apart from removing the faulty plugs, you’ll also have to be careful while tightening the new ones. You can refer to the owner’s manual for torque instructions, but if you over or under-tighten them, there will be issues.
For instance, if you under-tighten them, the spark plugs may come loose with the threads, whereas over-tightening can damage the plugs, leading to engine issues.
Considering the risks, it’s best to let an automotive expert deal with the spark plug change.
Fix the Spark Plug Issue with AutoNation Mobile Service
Worn-out spark plugs can lead to poor fuel economy, rough idling, and even engine damage if left unchecked. However, replacing spark plugs can be challenging as it also involves inspecting related parts like the plug wires and ignition coil pack. So trying to DIY with YouTube videos may not be a good idea.
Why not let the experts from AutoNation Mobile Service take care of the spark plug issue for you?
We offer upfront pricing, easy online bookings, and a 12-month | 12,000-mile repair warranty on all services, including an air filter, oxygen sensor, and fuel filter replacement.
Contact us to resolve your spark plug problem conveniently from your driveway.