IsItAGoodCar
Reliability Guide

Common Problems with the
2013 Smart Fortwo (451)

The 2013 exterior facelift revised the lower front and rear fascias and relocated the Smart badge inside the grille, while the 2011 interior update added knee airbags and a new instrument cluster. These late 451 models are the most refined of the generation, with the updated Mitsubishi 1.0-litre engine and optional MHD mild hybrid. The automated manual gearbox remains a potential weak point.

What changed for 2013

  • •2013 exterior facelift with revised fascias and relocated badge
  • •2011 interior update with knee airbags and new instrument cluster
  • •MHD mild hybrid drive continued
  • •Updated Mitsubishi 1.0-litre petrol engine

Common MOT watch-outs

  • !Clutch actuator failure on automated manual gearbox
  • !SAM unit corrosion from water ingress
  • !MHD drive belt failure on mild hybrid models
  • !Air conditioning condenser damage from road debris
3
Known Issues
2
Serious
1
Moderate
0
Minor

All Known Issues

MHD Drive Belt Failure

SeriousEngine

The Mild Hybrid Drive system uses a belt to start the engine and drive the water pump. If the belt snaps, the engine will overheat almost instantly, often warping the head.

Est. Repair Cost: £200 (belt) to £2,500 (engine rebuild)
Warning Signs:

Battery light on dash, Engine temperature warning, Sudden loss of power

What to Inspect:
  • Ensure the "Modified" belt kit and tensioner have been installed (Service Campaign work)
Verified by IsItAGoodCar Research Team

SAM Unit Corrosion (Water Ingress)

SeriousElectrics & Electronics

In the UK, water can enter the cabin via the door seals or heater intake and track down to the SAM unit (located in the passenger footwell).

Est. Repair Cost: £500–£1,000
Warning Signs:

Lights coming on by themselves, Dead battery, Non-start issues

What to Inspect:
  • Check for moisture under the passenger side carpet
Verified by IsItAGoodCar Research Team

Clutch Actuator Failure

ModerateGearbox & Transmission

The actuator that operates the clutch can seize or wear out, leading to jerky gear changes or failure to select drive.

Est. Repair Cost: £300–£600
Warning Signs:

Jerky pull-away, Slow gear changes, Car stuck in neutral with "3 bars"

What to Inspect:
  • Listen for a "creaking" noise from under the car when the ignition is turned on
Verified by IsItAGoodCar Research Team

Buying Tips for 2013 Smart Fortwo (451)

  • The 2013 facelift cars are the latest and most refined 451 examples
  • Verify the MHD service campaign belt kit has been fitted
  • Check for updated transmission software from the 2009 ECU upgrade
2009–20122014
Check a 2013 Smart Fortwo (451) by Registration