Mazda Spark Plug Replacement Guide DIY

Mazda Spark Plug Replacement DIY Guide, Cost, Gap

Learn how to change spark plugs on Mazda. Most Mazda models including Mazda 3, 5, 6, CX-5, CX-7, CX-9 require that spark plugs be replaced every 75,000 miles.

Replacing spark plugs on a Mazda engine requires a few basic tools and about two hours of work for most DIYers.



symptoms diy mazda spark plug replacement

Don't neglect to replace your Mazda spark plugs. If your spark plugs wear out you will notice problems such as: 

  • Check Engine Light On
  • Poor Engine Performance
  • Decrease in MPG
  • Engine idles roughly
  • Mazda engine misfires
  • Hesitation during acceleration
  • Fault Codes for cylinder misfire such as P0300, P0301, P0302, P0303, P0304.

What you will need

Replacing the spark plugs on a Mazda requires only a few basic tools and parts. 

Tools Required

Parts Required

  • Mazda Spark Plugs
    When it comes to choosing spark plugs for Mazda it can get difficult to decide what's best. The two options we would recommend are:
    1. NGK Iridium Spark Plugs. If you are looking for the best aftermarket spark plugs for Mazda a good choice are NGK Spark Plugs for Mazda. They come pre-gapped for Mazda and also have great reviews from Mazda owners. 
    2. OEM Mazda Spark Plugs
      OEM Mazda sparks plug at the dealer cost over $20 per spark plug. The NGK mentioned above are as good as the OEM plugs and even cheaper. If you prefer OEM spark plugs buy them online to save money. Check online price for Mazda OEM Spark Plugs

Instructions: Mazda Spark Plug Change

The following instructions show you how to change spark plugs on a Mazda four-cylinder engine. This is one of the most common Mazda engines found on Mazda3, Mazda5, Mazda6, CX-5, CX-7. 

Park vehicle

Park you Mazda on level ground. Allow the engine to cool down.

Open Hood

Pull the hood release on your MODEL and open the hood.​​​​​​​

Disconnect battery

Disconnect the negative battery terminal on your Mazda​​​​​​​

Remove Engine Cover

Remove the engine cover. Grab the engine cover with both hands and lift it up. In the following Mazda, there are no screws to secure the cover. Only tabs underneath the engine cover. 

how to change spark plugs mazda 3 5 6 cx 5 cx7 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019


Remove Ignition Coils

Unplug the electrical connector from the ignition coil. Press on the small tab then pull. Do this for all four coils. Remove the 10mm bolts that secure the coil in place. Pull the coils out.

Remove Spark Plugs

Use the spark plug socket, extension and ratched to remove the spark plugs from your Mazda. Use a magnetic pickup tool to pull out the spark plugs.

Install new spark plugs

Install new spark plugs on your Mazda. Ideally, you want to torque the spark plugs to spec (10-15 lb.ft.). If no torque wrench is available, tighten the spark plug finger-tight until the it reaches the cylinder head. Next tighten about half a  turn more with a ratchet.

Reinstall Ignition Coils

Reinstall coils and engine cover.

Reinstall Engine Cover

Mazda Spark Plugs Replacement Interval

replaced mazda spark plugs

According to multiple Mazda owner's manuals, the recommended interval to change spark plugs on a Mazda is every 75,000 miles.

If you install copper spark plugs on your Mazda you will need to replace them every 30,000 miles (in average) regardless of what the manual says.

Mazda Spark Plug Torque

Tighten the spark plug to approximately:

  • 7 to 15 lb. ft. for 14mm spark plugs.
  • 15 to 20 lb. ft. for 18mm spark plugs.

Mazda Spark Plug Gap

Mazda factory spark plug gap is typically in the .045 to .057 range.

Iridium spark plugs such as Denso Iridiums for Mazda come pre-gapped at 0.044 and should not be changed.

NGK Spark Plugs for Mazda come pre-gapped at 0.054. Do not gap iridium spark plugs.




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