Parts for your 2020 Ford Fiesta-Ignition coils

2020 Ford Fiesta ignition coils — what they do and when to service them

Technical sources including the Ford Workshop Manual for the Fiesta Mk8 (2017–), Ford service information (ETIS/Service Info), Haynes Ford Fiesta (2017–on) and Autodata confirm that 2020 Ford Fiesta petrol engines (1.0L EcoBoost, 1.1L Duratec and 1.5L EcoBoost ST) use coil-on-plug ignition coils. The 1.5L TDCi diesel variant does not use ignition coils because it relies on compression ignition and glow plugs. For any 2020 Fiesta running on petrol, ignition coils are very much relevant and fitted from factory.

On a 2020 Ford Fiesta petrol, each cylinder gets its own “pencil” coil mounted directly on the spark plug. Their job is to transform the 12V battery supply into the high voltage needed to jump the spark plug gap, lighting the fuel–air mix. Strong, consistent spark keeps the Fiesta’s little turbo triple (or the ST’s 1.5L) smooth, efficient and punchy across town and on the open road.

While coils aren’t a regular consumable like filters, they do live a hard life under the bonnet. Heat, vibration and worn spark plugs can all shorten their lifespan. It’s smart practice to inspect coils during major services, especially once the odometer pushes past higher kilometres. If there are misfire symptoms or fault codes, rule out basics first (plugs, lead-on connections, intake leaks) then evaluate the suspect coil with scan data and a swap test between cylinders.

• Common signs a coil is on the way out:
  • Rough idle, hesitation or flat spots under load
  • Check engine light with misfire codes (P0300–P0303 on 1.0L, etc.)
  • Poor fuel economy and exhaust sulphur smell from unburnt fuel

Service tips for the Fiesta’s ignition coils:

• Replace spark plugs at the interval in the Ford schedule, tired plugs stress coils.
• When refitting, keep coil boots clean and dry, a light smear of dielectric grease helps sealing.
• Avoid washing directly over the coil tops, moisture tracking can cause misfires.
• If one coil fails on a high‑kilometre car, consider the condition of the rest, but don’t replace a healthy set without evidence.

If the vehicle is a 2020 Fiesta diesel (1.5 TDCi), it won’t have ignition coils at all, that engine uses glow plugs to aid cold starts and ignites fuel by compression, which is why coils aren’t used on those models.

Popular questions about 2020 Ford Fiesta ignition coils

Does the 2020 Ford Fiesta have ignition coils?

Petrol models do — they use coil-on-plug units, one per cylinder. This is confirmed by Ford’s workshop documentation and standard parts listings for the 1.0L and 1.5L EcoBoost engines. The diesel 1.5 TDCi doesn’t use ignition coils because it relies on compression ignition, with glow plugs for cold starting.

How long do Fiesta ignition coils last?

There’s no fixed replacement interval. With fresh plugs and no contamination, coils can last many years and well over 100,000 kilometres. Replace a coil when there are misfire symptoms or diagnostic proof it’s weak. If one fails on a higher‑kilometre car, assess the others, but avoid blanket replacement unless testing suggests multiple weak coils.

Is it safe to drive with a bad ignition coil?

Best avoided. A persistent misfire can overheat and damage the catalytic converter and may wash fuel down cylinder walls. If the Fiesta is stumbling or the MIL is flashing, drive gently and get it checked promptly to prevent costly follow‑on damage.