Parts for your 2017 Ford Fiesta-Ignition coils

2017 Ford Fiesta ignition coils — what they do and when to replace them

Per Ford’s Workshop Manual for Fiesta (2013–2018, Section 303‑07A Ignition) and the Motorcraft parts catalogue, the 2017 Ford Fiesta petrol engines — including the 1.0‑litre EcoBoost three‑cylinder, 1.25/1.6 Duratec, and 1.6 EcoBoost ST — use individual coil‑on‑plug ignition coils (one per cylinder). Technical data sources such as Autodata and the Ford WSM diesel section (303‑04C) confirm the 1.5 TDCi diesel is compression‑ignition with glow plugs, so it does not use ignition coils.

On the petrol models, the ignition coils are the quiet achievers. They step up 12‑volt battery power to the thousands of volts needed to jump the spark plug gap, lighting off the air‑fuel mix under all loads and revs. The coil‑on‑plug layout mounts each coil directly over its spark plug, improving spark energy, reducing electrical losses, and helping with smooth starts, better fuel economy, and lower emissions.

Coils aren’t a scheduled service item, but they benefit from a quick once‑over during routine maintenance. It’s worth checking for stored misfire codes (P0300–P030X, P0351–P035X), perished boots, oil or moisture in the plug wells from a cam cover leak, and any arcing marks. Fresh spark plugs at the recommended interval (often 60,000–100,000 kilometres, engine‑dependent) take load off the coils and prolong their life.

Common signs a coil is on the way out include:

• Rough idle, hesitation under load, or a flashing check‑engine light
• Poor fuel economy, sulphury exhaust smell, or hard cold starts
• Misfire fault codes tied to a specific cylinder

Replacement is pretty straightforward: disconnect the battery, pop off the engine cover, unplug the connector, remove the small retaining bolt, and lift the coil and boot. Fit the new unit with a light smear of dielectric grease on the boot, seat it firmly, and avoid over‑tightening the bolt. Clear any codes and road‑test. Many owners replace just the failed coil, on high‑kilometre cars, doing the set can restore a smooth, even feel. Sticking with OE‑spec coils and the correct plug type and gap keeps the Fiesta happy.

If the car is a 1.5 TDCi diesel, ignition coils aren’t fitted or needed — that engine uses glow plugs and high compression to ignite fuel, so coil servicing doesn’t apply.

Popular questions about 2017 Ford Fiesta ignition coils

How long do ignition coils last on a 2017 Fiesta?
With healthy plugs and no moisture or oil in the plug tubes, many coils run well past 150,000 kilometres. Heat, vibration, and worn spark plugs are the usual coil killers. They’re replaced on condition — not by time — so inspection and proper plug maintenance go a long way.

Can you keep driving with a bad ignition coil?
It’ll usually run, but it’s a bad idea. Driving with an active misfire can overheat and damage the catalytic converter, wash fuel into the oil, and leave the car flat when you need power. If it’s missing, back off the throttle and get it checked or replaced promptly.

Do diesel 2017 Fiesta models have ignition coils?
No. The 1.5 TDCi diesel uses glow plugs and relies on compression for ignition, so there are no ignition coils to replace or service on those variants.