When Should You Change Spark Plugs?
Spark plugs are a small part with a big effect on how your car runs. A Cranbourne West specialist explains when to change them, the signs they’re worn, and why the right plugs matter.
How often plugs need changing
Intervals vary widely — from around 40,000 km on some performance and older engines to 100,000 km+ on modern long-life plugs. Your logbook sets the schedule, and we follow it with the correct plugs for your engine.
Direct-injection and turbo engines are often harder on plugs, so they may need them sooner.
Signs of worn spark plugs
Worn plugs show up as rough idling, hesitation or misfires, harder starting, poorer fuel economy, or a check-engine light for a misfire. Left too long, misfires can damage the catalytic converter — an expensive part.
If your car feels rough or down on power, plugs are one of the first things worth checking.
Why the right plug matters
Using the wrong plug type or heat range causes running problems and can damage the engine. We fit the correct manufacturer-specified plugs and gap/torque them properly — not just the cheapest box on the shelf.
Plugs are often done as part of a major service. Book in and we’ll check yours.
When Should You Change Spark Plugs? — FAQ
Anywhere from ~40,000 km to 100,000 km+ depending on the engine and plug type. We follow your logbook schedule.
Rough idle, hesitation or misfires, hard starting, worse fuel economy, or a misfire check-engine light.
Yes — persistent misfires can damage the catalytic converter, which is expensive. Don’t leave them too long.
Very much — the wrong type or heat range causes problems. We fit the correct specified plugs.
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Car running rough?
Trusted Cranbourne West car specialists — RACV-accredited, fixed written pricing. Book online or call 03 8782 0711.