Spark Plug Replacement Cost
Remove the ignition coils, swap the plugs, and re-gap if needed. Access can be tight on V6 and turbocharged engines.
What this repair is
Spark plugs ignite the air-fuel mixture in each cylinder. Over thousands of miles, the electrode gap widens and the plug wears, causing misfires, rough idling, and reduced fuel economy. Most plugs last 30,000 to 100,000 miles depending on type.
Signs you need this repair
- Rough idle or engine vibration
- Misfire or hesitation under acceleration
- Reduced fuel economy
- Check engine light with a misfire code
- Hard starting, especially when cold
What's included in the cost
DIY — what you pay for
- Spark plug set (4–8 plugs)$50
Shop — what they charge for
- Parts (plugs)$50
- Labor (1–2 hrs)$100
- Shop markup$40
DIY difficulty & what you need
Tools & parts
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When to call a shop instead
Doable for DIYers with the right socket and a torque wrench, but access can be very tight on V6, V8, and turbocharged engines where the rear bank is against the firewall. If you can’t easily reach all the plugs, a shop is reasonable.
Is your quote fair?
If a shop quotes above $230 for spark plug replacement on a 4-cylinder, ask why — V6 and V8 engines cost more due to access, but a 4-cylinder above that is high.
How to budget for this
Budget about $50–$65 in plugs for DIY or $190–$230 at a shop, every 60,000–100,000 miles depending on plug type (copper, platinum, or iridium).
Spark Plug Replacement FAQ
How long do spark plugs last?
Standard copper plugs last 30,000 miles, platinum plugs about 60,000, and iridium plugs up to 100,000 miles or more. Check your owner’s manual for the specified plug type and interval.
What happens if I don’t replace worn spark plugs?
Worn plugs cause misfires, rough idling, reduced fuel economy, and can damage the catalytic converter over time. A misfiring cylinder dumps unburned fuel into the exhaust, which overheats and ruins the catalytic converter.
Do I need to gap new spark plugs?
Yes, even 'pre-gapped' plugs should be checked with a gap gauge before installation. The correct gap is in your owner’s manual, typically 0.028 to 0.060 inches depending on the engine.
Sources
Cost estimates and maintenance intervals on this page are compiled from the following publicly available sources. Click through to verify or explore further.
Related repairs
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