Mazda Spark Plug Replacement Guide DIY
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.
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.
- 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:
- 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.
- 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 you Mazda on level ground. Allow the engine to cool down.
Pull the hood release on your MODEL and open the hood.
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.
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
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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