Car Repair Costs

How Much Does It Cost To Replace Spark Plugs?

The Average Cost to Replace Spark Plugs Is $66-$250, Depending on if You Go to the Mechanic or DIY.

  • Cost at the Mechanic: $191 – $250
    • Labor: $126 – $158
  • DIY Difficulty Level: Intermediate
  • Cost to DIY: $66 – $91
  • Urgency: Critical

*These prices are based on national averages according to RepairPal, and can vary greatly depending on where you live and what type of car you own. Related repairs or maintenance may also be needed. For a custom maintenance schedule based on your make, model, and mileage, download the free FIXD app.

What Are Spark Plugs?

Brand new spark plug (left) versus old, worn out spark plug (right).

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. 

The spark plugs on a 1997-2006 Jeep Wrangler are super easy to change out, but that isn’t the case with all cars/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

Claim Your Custom Maintenance Schedule

Get the FIXD Sensor and free app today for a custom maintenance schedule based on your make, model, and mileage. Never miss important maintenance again with automated maintenance alerts! 

Jeffrey-Ross

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

Jeffrey N. Ross
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

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6 Comments

  1. I already have a FIXD and it has saved me many, many, many $$$$.

  2. It’s a great information and tips for somebody that hus this kind of issues in their cars thank you for the info…

  3. I think I need to change my spark plugs in my Silverado Chevrolet V6 2008 next month

  4. Just glad to see Fixd info is back up and running, I appreciate all the info…Thanks

  5. I bought your fixd but when programing I put in the wrong engine and can not put in the right engine please help me

    1. Try uninstalling and installing again.

      Move slowly on the keyboard when entering data.

      If you uninstall an app or program from your phone, turn phone OFF and ON again before installing app or program again. DO NOT JUST AUTO STOP N START, turn OFF phone completely, then wait 5 mins. and turn ON again.

      Hope this helps.

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