CKFCar Known Faults
SevereAffected: 2012-201760,000–120,000 miles

Ford Fiesta Mk7 1.0 EcoBoost 100bhp — Suspension Coil Spring Snapping

A very common MOT failure in the UK. Suspension coil springs corrode and snap, usually near the bottom pigtail.

Severity

Severe

DIY Difficulty

Hard

Est. Cost

£150–£300

OBD Codes

None

Component Diagram

Suspension

Typical layout and location for the Suspension assembly.

Suspension diagram
Reference Illustration

Symptoms

  • Loud 'twang' or bang when turning the steering wheel at low speeds
  • Car sits noticeably lower on one side
  • Grating noise over bumps

Root Cause

The protective coating on the steel spring chips from stone impacts. Salt water corrodes the exposed steel, weakening the spring until it fractures under load.

How To Fix

  1. Visually inspect all four springs for fractures at the very bottom coil.
  2. Always replace coil springs in pairs across an axle to maintain handling balance.
  3. Cost: £150-300 per pair at an independent garage.

Estimated Repair Costs

Repair OptionEst. Cost (GBP)
DIY (parts only)£60–£120
Independent Garage£150–£300
Main Dealership£240–£480

Other Faults on This Variant

Timing Chain Stretch and Tensioner Failure

Critical
2012-201540,000–100,000 miles£600–£1200

Pre-2016 Ford 1.0 EcoBoost engines suffer from premature timing chain stretch. The plastic tensioner can fail, causing catastrophic engine damage with little warning.

Coolant Loss from Cylinder Head

Severe
2012-201860,000–120,000 miles£500–£900

The 1.0 EcoBoost has an integrated exhaust manifold cast into the cylinder head. This design causes head gasket stress and coolant loss, sometimes causing overheating.

Thermostat Failure and Overheating Risk

Moderate
2012-201850,000–100,000 miles£80–£180

The plastic thermostat housing on the 1.0 EcoBoost is prone to cracking. A stuck-open thermostat causes the engine to run cold and burn more fuel; a stuck-closed thermostat causes rapid overheating.

Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.