The Average Cost to Replace Spark Plugs Is $66-$250, Depending on if You Go to the Mechanic or DIY.
This price range is based on national averages for all vehicles and does not factor in taxes, fees, or your particular make and model. Related repairs or maintenance, such as O2 sensor replacement, fuel filter replacement, and new spark plug wires, may also be needed. For a more accurate estimate cost to replace spark plugs based on your make, model, and location, use the Repair Pal Fair Price Estimator.
Get a more accurate estimate for your spark plug replacement using RepairPal's Fair Price Estimator:
Cost at the Mechanic: $191-$250
- Parts: $66-$91
- Labor: $126-$158
Replacing the spark plugs on a vehicle is a maintenance item that usually takes between one and four hours to complete, depending on the vehicle and if other repairs are needed. This service should be completed about every 30,000 miles, or as specified by your owner’s manual.
Cost to DIY: $66-$91
- Difficulty level: Intermediate
- Parts needed:
You can reduce the cost to replace spark plugs by doing this job yourself. Your exact replacement cost will also depend on how many spark plugs are needed (typically between 4 and 16) and whether you choose long-life platinum-tipped spark plugs or cheaper conventional ones.
Keep in mind: There are many different types of spark plugs, and not all plugs fit all vehicles. If you plan to replace your spark plugs yourself, be sure to choose the right parts to fit your vehicle. When in doubt, always refer to your owner’s manual.
What Are Spark Plugs?
Spark plugs are as important to your engine as the gasoline in your tank. As the name suggests, the spark plug creates a spark in the combustion chamber to ignite the air/fuel mixture, which drives your engine. Most engines feature one spark plug per cylinder, but some newer, more advanced engines feature two spark plugs per cylinder. It is extremely important that your vehicle’s spark plugs are functioning properly to maximize reliability and fuel efficiency, so be sure to replace spark plugs regularly.
How To Replace Spark Plugs?
The spark plug screws into the cylinder and head, and they are connected using either plug wires or coil packs. Knowing how to replace spark plugs is basically the same across all types of engines, but this job tends to be easier on vehicles equipped with an inline engine rather than wider V-6 or V-8 engines.
What Happens If You Don’t Replace Spark Plugs?
Only in the most absolute worst-case scenario would an old spark plug create a safety issue or cause damage to your engine, but worn out spark plugs will definitely affect the performance of your engine. If you don’t replace the spark plugs at the recommended intervals, you’re most likely going to suffer from a rougher idle and reduced fuel economy, but waiting too long could result in reduced reliability and even being stranded on the side of the road.
How Often Should You Replace Spark Plugs?
Most automakers recommend replacing the spark plugs every 30,000 miles or so, but be sure to check your owner’s manual or use the free FIXD app for accurate maintenance schedules. Replacing spark plugs can definitely be an easy DIY repair, but it all depends on the specific vehicle and engine type.
Common Symptoms You Need to Replace Spark Plugs
- Engine running rough
- Code P0300 engine/cylinder misfire
- Visual inspection shows worn spark plug electrode
Related Maintenance Services
- Replace spark plug wires
- Serpentine belt replacement
- Fuel system service
- Clean/replace mass air flow sensor
- Replace air filter
Track Spark Plug Replacement with FIXD
Want to stay on top of routine maintenance so you can save money and keep your car running smoothly longer? Get the FIXD Sensor and free app today for a custom maintenance schedule based on your make, model, and mileage. FIXD tracks important maintenance and wear items for you and sends automated alerts so you can maintain your car on autopilot.
Lifelong automotive enthusiast with a soft spot for offroading. Wrencher turned writer, but I still love to tinker on just about anything with an engine. Dream car: tie between a ‘71 Hemi ‘Cuda and a ’91 GMC Syclone. #GirlDad #SaveTheManuals