Parts for your 2015 Subaru Xv-Ignition coils

2015 Subaru XV ignition coils — what they do and how to look after them

Technical references, including the Subaru factory workshop manual for the FB20 2.0‑litre petrol engine, Subaru’s Service Information (STIS), and the genuine Subaru parts catalogue for MY2015 XV (GPE/GPD), specify a direct, coil‑on‑plug ignition system with four individual ignition coils. That means ignition coils are fitted and relevant to the 2015 Subaru XV petrol models. Note: markets that offered the EE20 2.0D diesel XV won’t use ignition coils, as diesels rely on compression ignition and glow plugs rather than spark.

On the 2015 XV 2.0i petrol, the ignition coils live directly on top of each spark plug. Their job is to take the 12‑volt feed and step it up to tens of thousands of volts, creating a strong spark at precisely the right moment. Coil‑on‑plug keeps the spark energy high and consistent, helps cold starts, trims fuel use, and cuts down emissions.

These coils aren’t a routine “change by date” item, but they do benefit from regular checks during servicing. When the spark plugs are due (typically around the 100,000 km mark for iridium plugs, per Subaru schedules), it’s smart to inspect each coil for hairline cracks, heat discolouration, swelling of the rubber boot, or corrosion on the terminal. Any oil inside the plug tubes points to a rocker cover gasket leak that can shorten coil life—fix the leak and clean the tubes before refitting.

Common signs a coil is on the way out include a rough idle, hesitation or shudder under load, higher fuel use, and a flashing or steady Check Engine Light with misfire codes (often P0301–P0304). If a coil fails intermittently, it can let unburnt fuel reach the cat, so don’t leave misfires unattended.

Replacement is straightforward: disconnect the connector, remove the hold‑down bolt, twist and pull the coil out, then refit in reverse. Use quality OEM or reputable aftermarket coils, keep the boots and plug bores clean and dry, and apply a light smear of dielectric grease to the inside of the boot only. Tighten hardware to the factory spec and clear any fault codes, then road‑test. On higher‑kilometre cars, replacing coils in pairs—or all four if there’s a pattern of failures—can save repeat visits.

For Aussie and Kiwi conditions—heat, dust, and the odd water crossing—periodic visual checks are worth it. After deep water or a steam clean, make sure the plug wells are bone dry before starting to avoid tracking and premature coil damage.

How often should ignition coils be replaced on a 2015 Subaru XV?

They’re not a scheduled service item. Many last well past 150,000 km. Inspect them whenever the spark plugs are out or if there’s a misfire. Replace only if there are symptoms, damage, or persistent misfire codes. On high‑kilometre cars with multiple coil faults, replacing all four can be cost‑effective.

What are the tell‑tale signs of a failing ignition coil on an XV?

Rough idle, hesitation under load, poor fuel economy, a sulphur smell from the exhaust, and a Check Engine Light with P0301–P0304 misfire codes. Sometimes the issue is worse in the wet or right after a hot soak. Visual cracks or oil in the plug tubes are red flags.

Can a bad coil damage the catalytic converter?

Yes—driving with a persistent misfire can send unburnt fuel into the cat, overheating and damaging it. If a misfire pops up, avoid heavy load, get the codes scanned, and sort the coil, plug, or gasket issue promptly.