Home / Common Problems / Smart (mcc) Fortwo Coupe

Smart (mcc) Fortwo Coupe Problems & Known Issues

The most common Smart (mcc) Fortwo Coupe problems ranked by severity — what to watch for, what it costs to fix, and what happens if you ignore it.

Generations

450 — First Generation
1998–2007
0.7 Turbo, 0.7 CDI, 0.8 CDI, 0.8 CDI, 1.0 Turbo, 1.0 CDI
451 — Second Generation
2007–2014
1.0 MHD, 0.8 CDI
453 — Third Generation
2014–2020
0.9 Turbo, 0.9 CDI

Top issues to watch for

The most serious Smart (mcc) Fortwo Coupe problems ranked by severity. We track 5 known issues — here are the ones you need to know about first.

Dangerous
Brake hose deterioration
4501998–20070k–150k miles
Flexible brake hoses on first-generation Smart Fortwo deteriorate at 33 times the national fleet average, particularly on 0.7-litre petrol models. The hoses are positioned close to the rear-mounted engine and suffer from heat cycling and vibration. Internal deterioration can cause the hose to collapse under braking, leading to complete brake failure. This is a safety-critical issue that affects cars across all mileage ranges including very low-mileage examples.
What happens if ignoredFailed brake hoses can cause complete brake failure without warning. The small brake system means pressure loss affects all wheels quickly. This is a safety-critical defect that makes the vehicle dangerous to drive. Hose replacement is typically £80-150 per corner but must be done immediately when deterioration is detected.
Independent garage
£200–£350
Specialist
£250–£400
Main dealer
£300–£500
Parts only
£80–£150
Major
Engine mount failure
450, 4511998–201420k–120k miles
Engine mounts on Smart Fortwo fail at exceptionally high rates due to the engine's rear-mounted position and constant transmission vibration from the automated manual gearbox. The rubber deteriorates and separates from the metal brackets, causing excessive engine movement that can damage surrounding components.
What happens if ignoredFailed engine mounts allow excessive engine movement that can damage exhaust pipes, electrical connections, and cooling hoses. In extreme cases, the engine can shift enough to interfere with gear selection. Replacement typically costs £200-400 per mount, with most cars requiring all three mounts by 80,000 miles.
Independent garage
£300–£500
Specialist
£400–£600
Main dealer
£500–£800
Parts only
£150–£300
Major
Fuel system leaks
450, 4511998–201420k–120k miles
Fuel system leaks occur at 29.6 times the fleet average on petrol Smart Fortwo models, with 0.7-litre variants particularly affected around 40,000-60,000 miles. The rear-mounted fuel tank and associated pipework are subject to engine heat and vibration. Leaks commonly develop at fuel line connections, the filler neck seal, or the fuel pump mounting. The small fuel tank means even minor leaks represent a significant safety hazard in the confined rear engine bay.
What happens if ignoredFuel leaks in the rear engine bay present a serious fire risk due to the proximity of hot engine components and electrical connections. Even small leaks must be repaired immediately. Depending on the location, repairs can range from £100 for a simple hose replacement to £500+ if the fuel tank or pump requires removal.
Independent garage
£150–£400
Specialist
£200–£500
Main dealer
£250–£650
Parts only
£50–£200
Major
Coil spring failure
450, 4511998–20140k–100k miles
Coil springs fracture at 10.8 times the fleet average on Smart Fortwo, affecting all engine variants but particularly severe on 0.7-litre petrol models even at very low mileages. The short, stiff springs required for the compact wheelbase are prone to metal fatigue and can fracture without warning. Spring failure can occur on cars with fewer than 20,000 miles, indicating a design limitation rather than normal wear.
What happens if ignoredA fractured coil spring can collapse completely without warning, causing loss of vehicle control and potential tyre damage. The broken spring can also damage brake lines, suspension arms, or wheel arch liners. Replacement typically requires both springs on an axle to maintain handling balance, costing £200-400 depending on which axle is affected.
Independent garage
£180–£320
Specialist
£220–£380
Main dealer
£280–£450
Parts only
£80–£160

1 more known issues tracked

Including wear items, electrical niggles, and generation-specific problems. Check a specific car to see which issues apply to its age and mileage.

Check a specific car →

MOT failure hotspots

Based on DVSA MOT test data. These are the items where the Smart (mcc) Fortwo Coupe fails at a significantly higher rate than the average car.

Fuel system leaking, or missing or ineffective ...
Bodywork · 0-20k miles
MOT failure rate: 73x the fleet average
Sample: 540 tests
Engine mounting/bracket severely damaged or det...
Bodywork · 20-40k miles
MOT failure rate: 47x the fleet average
Sample: 17,431 tests
Emissions failure
Exhaust & Emissions · 40-60k miles
MOT failure rate: 44x the fleet average
Sample: 3,941 tests
Brake hoses perished or damaged
Brakes · 0-20k miles
MOT failure rate: 33x the fleet average
Sample: 1,405 tests
Tyre valve seriously damaged or misaligned
Tyres · 0-20k miles
MOT failure rate: 27x the fleet average
Sample: 2,368 tests
Headlight fault
Lights & Electrics · 20-40k miles
MOT failure rate: 25x the fleet average
Sample: 2,010 tests

Buying a Smart (mcc) Fortwo Coupe?

Check a specific car's service history to see if it's been looked after — franchised dealer records with dates, mileage, and work done.

Check service history

£6.99 · Full refund if no records found

Related

Smart (mcc) Fortwo Coupe reliability FAQs

What are the most common problems with the Smart (mcc) Fortwo Coupe?

The Smart (mcc) Fortwo Coupe has 5 known issues across 3 severity levels. The most serious are: Brake hose deterioration.

Is the Smart (mcc) Fortwo Coupe reliable?

The Smart (mcc) Fortwo Coupe has 1 dangerous and 3 major known issues. Most can be avoided with a thorough pre-purchase check and full service history.

How much does it cost to fix Smart (mcc) Fortwo Coupe problems?

Repair costs range widely. The most significant issue (Brake hose deterioration) costs £200–£350 at an independent garage. Minor issues can be under £200. Always get a full inspection before buying.

Which Smart (mcc) Fortwo Coupe generation is most reliable?

The 451 (2007–2014) has the fewest dangerous issues (0). However, condition and service history matter more than generation — a well-maintained earlier car can be more reliable than a neglected newer one.