Fiat 500 0.9 TwinAir 85bhp — Suspension Coil Spring Snapping
A very common MOT failure in the UK. Suspension coil springs corrode and snap, usually near the bottom pigtail.
Severity
SevereDIY Difficulty
Hard
Est. Cost
£150–£300
OBD Codes
None
Suspension
Typical layout and location for the Suspension assembly.
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
- Visually inspect all four springs for fractures at the very bottom coil.
- Always replace coil springs in pairs across an axle to maintain handling balance.
- Cost: £150-300 per pair at an independent garage.
Estimated Repair Costs
| Repair Option | Est. Cost (GBP) |
|---|---|
| DIY (parts only) | £60–£120 |
| Independent Garage | £150–£300 |
| Main Dealership | £240–£480 |
Other Faults on This Variant
Timing Belt Failure (Short 36,000-Mile Interval)
CriticalThe 0.9 TwinAir engine has an unusually short timing belt interval of just 36,000 miles or 3 years. This is poorly publicised and many owners miss it. Belt failure destroys the engine.
TwinAir UniAir Module Failure
CriticalThe 0.9 TwinAir engine uses a complex electro-hydraulic 'UniAir' module to actuate the intake valves instead of a traditional camshaft. This module fails if oil changes are neglected.
Dual Mass Flywheel Failure (TwinAir only)
SevereUnusually for a tiny petrol engine, the two-cylinder TwinAir requires a Dual Mass Flywheel to smooth out its intense vibrations. This DMF wears out surprisingly fast.
Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.