2016–2024 Mazda CX-3
By Ray Delgado ✓ Certified Mechanic · Published Sep 21, 2026 · Updated Oct 22, 2026
Save $335 by doing it yourself! Shop cost: $450
Quick answer: Spark Plug Replacement on a 2016–2024 Mazda CX-3 is rated Advanced and takes about 45 minutes–1 hour. You'll need 6 tools for this job, and parts cost about $115. This guide walks you through the full job step by step, including the mistakes to avoid.
| Part Name | Part Number | Price | Buy |
|---|---|---|---|
| Correct spark plug set for the gasoline/ICE engine in 2016-2024 Mazda CX-3; verify engine, heat range, gap, and VIN fitment | — | $115.00 | |
| Coil-boot seals or ignition coils only if inspection finds damage Optional | — | $35.00 |
About prices: shown prices are typical retail averages and change frequently; cheaper alternatives may be available. Confirm the current price before buying.
💡 Pro tip: Order all parts at once to save on shipping
Follow these steps carefully
Park on level ground, open the hood, and allow several hours after driving. For extra safety while handling ignition components, disconnect the negative battery terminal before you start.
The CX-3's black plastic engine cover is not bolted down — it sits on four rubber friction posts molded into the valve cover. Grip the cover firmly at the corners and pull straight up; it releases with a firm tug.
This two-minute step prevents the most common — and most expensive — DIY damage of this job. Before anything comes off, clear debris from around each coil and down each plug well with compressed air.
Squeeze the locking tab on each coil's wiring connector and pull the connector free — never tug on the wires themselves. Each coil is held by a single small retaining bolt (typically 8mm on these cars; confirm visually before buying sockets). Remove the bolt, then pull the coil straight up with a gentle twisting motion; the rubber boot can stick to the plug after years of heat, so be patient rather than levering against the valve cover. Lay the coils out in order even though coil-on-plug coils are identical — if one coil boot is oil-fouled or cracked, you will know exactly which cylinder it came from when you inspect them.
Squeeze the locking tab on each coil's wiring connector and pull the connector free — never tug on the wires themselves. I don't skip this anymore.
Measure every plug with a wire-type gap gauge — never drag a flat coin-style gauge across the fragile iridium center electrode, which can chip it.
I've been burned by this before: Do not invent or guess a gap value: find the exact specification on the emissions sticker under the hood or in the owner's manual.
The SkyActiv-G's aluminum cylinder head makes cross-threading and overtightening expensive mistakes. Drop each new plug into the spark plug socket with its rubber insert and thread it in by hand — extension only, no ratchet — turning it backwards half a turn first until you feel the threads click into place, then clockwise. It should spin freely all the way down with finger pressure; any binding means back it out and start again. Once finger-tight, snug it per the plug manufacturer's box instructions (typically a fraction of a turn past finger-tight for a washer-seat plug). Many modern iridium plugs ship with pre-coated threads, so follow the plug maker's guidance on anti-seize rather than applying your own.
Push each coil firmly back onto its plug until the rubber boot seats fully, reinstall the small retaining bolts snug (these thread into aluminum — gentle does it), and reconnect each wiring connector until the locking tab clicks. A dab of dielectric grease inside the coil boot eases the next removal and seals out moisture; keep it off the plug's metal terminal faces. Pop the engine cover back onto its four friction posts, reconnect the battery if you disconnected it, and start the engine. Let it idle and watch for a flashing check-engine light — if a cylinder misfires, shut down immediately and recheck that coil's connector seating before anything else. Finish with a short test drive under light load; a smooth idle and normal power mean the job is done.
Test your repair before closing everything up. If something doesn't work right, double-check your steps.
⚠️ Common Mistakes to Avoid
Acura CL · 2001–2003
Acura ILX · 2013–2022
Acura Integra · 2023–2026
Acura MDX · 2017–2021
Acura RDX · 2019–2024
Acura RL · 2005–2012
Acura TLX · 2015–2020
Acura TSX · 2004–2008
