UK Buyer Reliability Guide3 Known Faults Documented

Smart Forfour (454) Common Problems & Reliability

The first-generation Smart Forfour (Type 454) was a conventional, front-engine, front-wheel-drive supermini developed alongside the Mitsubishi Colt. It abandoned the rear-engine layout of the Fortwo to offer a spacious, four-seat cabin with sliding rear seats and quirky two-tone plastic bodywork. In the UK, it was a slow seller and is now a rare sight, mostly remembered for its Brabus high-performance version. Reliability is generally very good thanks to the Mitsubishi-sourced engines and electronics, making it a dependable, if unconventional, cheap runaround. It suits budget buyers who want a reliable, practical small car that stands out from a typical Ford Fiesta.

1
Generation Periods
3
Known Issues
1
Critical Faults
2
Moderate Issues

Select a Model Year Period

Detailed fault breakdown, symptoms, and estimated repair bills by production year.

Most Common Smart Forfour (454) Faults & Repair Costs

High Risk

Clutch Actuator Failure

Est. Cost£400–£800

The automated manual gearbox uses an electric actuator that can fail, leaving the car unable to select gears.

Warning Signs:

Stalling when stopping, Refusal to engage gear, Warning light on dash

Moderate Risk

Rear Wheel Bearing Failure

Est. Cost£150–£300

Rear bearings are a known weak point and can start to drone or hum.

Warning Signs:

Droning noise from the rear that increases with speed

Moderate Risk

Front Suspension Wear

Est. Cost£150–£400

Wishbone bushes and anti-roll bar links wear out, leading to knocks and poor handling.

Warning Signs:

Knocking over bumps, Car pulling to one side

Essential Pre-Purchase Step

Buying a used Smart Forfour (454)? Always check for hidden finance and write-off history.

Mechanical problems are only half the battle. Over 1 in 3 UK used cars checked have unpaid finance or accident write-off records that could cause you to lose the car or thousands in value.

Inspection Checklist for Smart Forfour (454) Buyers

Check the plastic body panels for cracking or severe fading, particularly the roof panels which suffer under UV light.
Listen for timing chain rattle on the Mitsubishi-sourced petrol engines, particularly on high-mileage cars.
Verify the operation of the automated manual "Softouch" gearbox (if fitted); it can be jerky and the clutch actuator is a known weak point.
Test the sliding rear seat mechanism to ensure it moves smoothly and locks securely into place.
Inspect the front suspension for knocking; drop links and anti-roll bar bushes wear quickly.
Check the central locking system, as the door lock actuators frequently fail.