Quick answer: Spark Plug Replacement Easy Job on a 2013–2016 Mazda CX-5 is rated Moderate and takes about 1 hour. You'll need 7 tools for this job, and parts cost about $40. This guide walks you through the full job step by step, including the mistakes to avoid.
| Part Name |
Part Number |
Price |
Buy |
| NGK Laser Iridium Spark Plugs |
ILKAR7L11 |
$35.00 |
|
| Dielectric Grease |
— |
$5.00 |
|
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
Step-by-Step Instructions
Follow these steps carefully
1
Cool the engine (use genuine NGK!)
The 2013–2016 Mazda CX-5 (2.0L or 2.5L SkyActiv-G) uses NGK iridium plugs. 2.5L: NGK ILKAR7L11. 2.0L: different part (verify). Gap: 1.05–1.15mm (pre-gapped, do not adjust). Torque: 12–14 ft-lbs. You'll need: 4x correct NGK plugs for your engine, spark plug socket, extension. Critical: let the SkyActiv engine cool — aluminum heads. Important: the ECU uses the spark plug as a KNOCK SENSOR — use ONLY genuine NGK (no counterfeits). Counterfeit plugs cause knock-sensor errors and drivability issues. Buy from a reputable source. The CX-5's plugs are easy top-access. Interval: 75,000 miles (Mazda spec — shorter than many iridium intervals).
🔧 Mechanic's note — Ray Delgado
I let the CX-5 cool and I use genuine NGKs torqued to spec — I have seen a plug back out of an aluminum head installed by feel, and the damage on the way out is ugly. The wrench clicks or I redo it.
2
Access the ignition coils
Remove the engine cover. No intake removal. The 2.0L and 2.5L have the same layout — just different plug parts. Unplug any connectors blocking access. The CX-5's bay is straightforward — this is a quick job.
3
Remove one coil at a time
Unplug the connector, unbolt the coil, pull it straight out. The SkyActiv's high compression (13:1) means the plugs work hard — but the coils are up to it. Don't mix up the coils.
4
Remove the old spark plug
Remove the old NGK plug with your socket. The old ILKAR7L11 (2.5L) should show normal SkyActiv wear. If a plug is oil-fouled, check the valve cover. The CX-5's plug wells are shallow — easy removal. Don't drop anything in. Note: the ECU's knock-sensing relies on the plug's ion signal — a worn plug affects knock detection.
5
Gap and hand-thread (genuine NGK only!)
The new NGK iridium comes pre-gapped at 1.05–1.15mm — DO NOT re-gap (iridium). Verify it's genuine NGK — counterfeits are common and the CX-5's knock-sensing ECU will malfunction with fake plugs. Hand-thread the new plug until it seats. NEVER wrench-start — the SkyActiv's aluminum head strips. If it binds, back out. Ensure correct part: ILKAR7L11 for 2.5L (verify for 2.0L).
6
Torque to 12-14 ft-lbs
Torque to 12–14 ft-lbs. Use a torque wrench. Do not over-torque — the aluminum head strips. The easy top access means precise torquing is simple. The knock-sensing plug needs proper torque for good electrical contact — don't under-torque either.
7
Reinstall the coil
Reinstall the coil — seat it firmly, bolt it down, reconnect the connector (click). Repeat for all 4, one at a time. Reinstall the engine cover. Verify all connectors are clicked.
🔧 Mechanic's note — Ray Delgado
I reinstall the CX-5 coil and listen for the click — then I tug it. The SkyActiv coils sit deep in the wells, and I have had one that felt seated back out from vibration. The tug test is my proof.
8
Reassemble and test
Start the engine — the SkyActiv should idle smoothly with its high-compression character. Check for misfire or knock-sensor codes. The CX-5's ECU uses the plug for knock detection — if you used counterfeit plugs, you'll get knock-sensor errors. Test drive: the CX-5 should accelerate cleanly. The 75,000-mile interval is shorter than typical iridium — Mazda knows the SkyActiv works plugs hard. Use ONLY genuine NGK ILKAR7L11 (2.5L) — the knock-sensing system depends on it. If you have drivability issues after, suspect counterfeit plugs first.
🔧 Mechanic's note — Ray Delgado
I take the CX-5 around the block after plugs — a steady idle in the bay means little. I want to feel clean throttle response and hear no stumble, because that is what the owner will notice first.
All Done!
Test your repair before closing everything up. If something doesn't work right, double-check your steps.
⚠️ Common Mistakes to Avoid
- • Not properly gapping the new spark plugs
- • Over-tightening the spark plugs
- • Failing to apply dielectric grease to the ignition coil boots
- • Not cleaning the spark plug wells before installation
- • Using incorrect spark plug type or heat range
