Skip to content
MotorFiable
en

Smart carsCode W453

Smart Forfour problems (2014–2021)

The only engine of the Smart Forfour that we have documented, the 0.9 TCe, has high or critical severity faults in the versions it is fitted to. Our verdict for the version it is fitted to: «With caution».[1][2]

Outside the engine: Apart from the engine, the Smart Forfour (W453) has no chronic faults documented in the sources we were able to open; what there are is preventive recalls (handbrake, front hub carrier, rear seat backrest anchorage and selector cable) and the 12 V battery as a typical weak point on 2015 to 2017 cars according to ADAC statistics.[3][4][5][6][7]

Smart Forfour (2014–2021)
Photo: M 93 · CC BY-SA 3.0 de · Wikimedia Commons. Reference image for this generation.
02468105.3out of 10

Smart Forfour rating: acceptable reliability

Calculated using only 10 documented faults and their sources: the most serious and frequent faults weigh more. How it is calculated

  • Engine5.15 faults
  • Gearbox7.91 fault
  • Suspension7.11 fault
  • Brakes7.91 fault
  • Tyres and wheels10.0No documented faults
  • Steering10.0No documented faults
  • Electrical system8.61 fault
  • Electronics and infotainment10.0No documented faults
  • Climate control10.0No documented faults
  • Bodywork and interior10.0No documented faults
  • Airbags and safety7.91 fault

Ranked 15 of 16 among the city cars with solid evidence. See the ranking

The weak points of the Smart Forfour

  1. 1High severity: Coolant leak at the thermostat housing0.9 TCe engine
  2. 2Critical severity: Timing chain or tensioner failure0.9 TCe engine
  3. 3Critical severity: Front left hub carrier with insufficient strength (2017 campaign)Suspension
  4. 4High severity: Handbrake: the lever gains travel because of the cable adjustment and may not hold the carBrakes
  5. 5High severity: Rear seat backrest anchorage with insufficient strength in a frontal crashAirbags and safety

Documented engine

The first label is the most serious fault affecting that engine in this car; the second, our verdict for the versions it is fitted to. Each engine's risk index is calculated only from the faults that affect this car (how we calculate it). We only show engines we have documented with sources: if yours does not appear, we have not analysed it yet. View all engines

See what to check before buying

Outside the engine

6 recalls and campaigns documented, the latest: DVSA R/2017/252: incorrectly manufactured hub carrier. See the campaigns for the Smart Forfour

9 sourcesHow we work

0.9 TCe

Renault-Nissan-Daimler 0.9 TCe (H4Bt / M281 / Nissan HR09DET) · Petrol

In the Forfour
2014–2019[8][9]
Faults that affect it
5 · 3 of high or critical severity
Risk index on this car
49
Moderate risk

Verdict for the version it uses

  • 0.9 TCe 90 (H4Bt, 2012-2024)

    2012–2024 · 90 hp · H4Bt-400, H4Bt-408, H4Bt-410

    With caution

    The reliability record is positive and better than that of its sibling the 1.2 TCe, without the oil consumption or rate of chain problems so well documented for that engine. Check the coolant history (leak at the thermostat housing) and, to a lesser extent, any history of noise or work on the timing chain before buying.[1][2]

Faults that affect the Forfour

  1. High severityCommonFrequency: CommonCoolingCoolant leak at the thermostat housingThe 0.9 TCe can lose coolant through the thermostat housing (calorstat) gasket. It is the most-cited fault of this engine: if not detected in time, the low level can end up damaging the head gasket.
  2. Critical severityOccasionalFrequency: OccasionalTimingTiming chain or tensioner failureThe 0.9 TCe's timing chain tensioner can lose effectiveness over time. It is a minority of cases, but when the chain jumps the damage is serious: there is a documented case with a complete engine replacement at 80,000 km.
  3. High severityRareFrequency: RareTurboTurbocharger wear or failureThe 0.9 TCe's turbo can lose performance or fail, although the available statistics put it as an infrequent fault on this specific engine.
  4. Low severityRareFrequency: RareInjectionJerking due to an injection calibration that needs reprogrammingSome 0.9 TCe engines show slight jerking when accelerating because of an injection calibration that is corrected by reprogramming the ECU, without it being mechanical damage.
  5. Low severityRareFrequency: RareLubricationOil consumption (uncommon on this engine)Unlike other engines in the same family, the 0.9 TCe does not show a widespread pattern of excessive oil consumption: the sources document only a minority of cases.

Forfour 0.9 TCe pageAll versions and faults of the 0.9 TCe

Faults of the Smart Forfour outside the engine

Suspension, brakes, tyres, electronics and the rest of the car. They occur with any engine.

Checklist for buying a used Smart Forfour

Check the advert or the paperwork to see which engine the car has and go through its section. Each point comes from a documented fault; you can tick them off as you inspect.

If it has the 0.9 TCe (2014–2019)

Coolant leak at the thermostat housing

High severity

Timing chain or tensioner failure

Critical severity

Turbocharger wear or failure

High severity

Jerking due to an injection calibration that needs reprogramming

Low severity

Oil consumption (uncommon on this engine)

Low severity

Buying a Smart Forfour?

We will put you in touch with a partner only if you authorise it in the form.

Own a Smart Forfour? Tell us what faults you have had, at what mileage and how much you paid. Report your fault.

Frequently asked questions

Is the Smart Forfour reliable?

The only engine of the Smart Forfour that we have documented, the 0.9 TCe, has high or critical severity faults in the versions it is fitted to. Our verdict for the version it is fitted to: «With caution». Apart from the engine, the Smart Forfour (W453) has no chronic faults documented in the sources we were able to open; what there are is preventive recalls (handbrake, front hub carrier, rear seat backrest anchorage and selector cable) and the 12 V battery as a typical weak point on 2015 to 2017 cars according to ADAC statistics.

What problems does the Smart Forfour have apart from the engine?

Apart from the engine, the Smart Forfour (W453) has no chronic faults documented in the sources we were able to open; what there are is preventive recalls (handbrake, front hub carrier, rear seat backrest anchorage and selector cable) and the 12 V battery as a typical weak point on 2015 to 2017 cars according to ADAC statistics. The most important documented faults are: front left hub carrier with insufficient strength (2017 campaign) (suspension, critical severity), handbrake: the lever gains travel because of the cable adjustment and may not hold the car (brakes, high severity), rear seat backrest anchorage with insufficient strength in a frontal crash (airbags and safety, high severity) and gear selector bowden cable that can come loose and stop P engaging or disengaging (gearbox and clutch, high severity).[3][4][5][6][7]

What faults does the Smart Forfour have?

The most important by severity and frequency, on the engines we have documented, are: coolant leak at the thermostat housing (0.9 TCe, high severity), timing chain or tensioner failure (0.9 TCe, critical severity), turbocharger wear or failure (0.9 TCe, high severity), jerking due to an injection calibration that needs reprogramming (0.9 TCe, low severity) and oil consumption (uncommon on this engine) (0.9 TCe, low severity).

What is the best year to buy a Smart Forfour?

According to our rating by year, the best are 2019 and 2018 (7.5/10); the worst rated is 2015 (5.7/10). Each year's rating counts only the engines sold that year and the faults that affect those units: open each year to see what changes.

Does the Smart Forfour have recalls?

Yes: we have documented 6 campaigns for the Smart Forfour, such as DVSA R/2017/252: incorrectly manufactured hub carrier (2017). Check with your VIN at the official service centre whether yours has been done.[6]

Sources

Every fact on this page links to its source. If you find an error, let us know.

  1. 1.Moteur H Renault-NissanWikipedia (francés) · Other source · consulted 27 September 2026 · in French
  2. 2.Fiabilité des 0.9 TCeFiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  3. 3.Recall: Smart Forfour (2014 - 2015) accident, brakescar-recalls.eu · Other source · published 29 September 2017 · consulted 5 October 2026
  4. 4.Recall: Smart ForFour (2017) accident, steeringcar-recalls.eu · Other source · published 13 October 2017 · consulted 5 October 2026
  5. 5.Smart ForFour (2014-2015): rear seat backrest anchorage defectcar-recalls.eu · Other source · published 23 June 2016 · consulted 5 October 2026
  6. 6.DVSA – base de llamadas a revisiónDVSA (Reino Unido) · Other source · consulted 5 October 2026
  7. 7.Reliability of the Smart ForFour (ADAC breakdown statistics)car-recalls.eu · Other source · consulted 5 October 2026
  8. 8.Mercedes-Benz M281 engineWikipedia (inglés) · Other source · consulted 27 September 2026
  9. 9.Smart ForfourWikipedia (inglés) · Other source · consulted 27 September 2026