Common problems
Mercedes-Benz SLC common problems
What MOT testers find on the Mercedes-Benz SLC: the parts that fail or get advisories most often at each age, against all cars of the same age. From 35,306 DVSA MOT tests taken 2022 to 2025.
MOT data updated
At 6 years, the most tested age
What stands out
- Tyres fails show up on 7.2 of every 100 MOTs of a Mercedes-Benz SLC at 6 years old (n=8,273), against 5.6 for all cars of that age (n=10,382,720).
- Lights and electrics fails are less common: 1.7 per 100 MOTs against 4.7 for all cars at the same age.
- The fail item testers record most often at 6 years: tyre with cords exposed, on 2.7 per 100 MOTs (all cars 1.0).
- The most common advisory or minor defect: tread depth: worn close to legal limit/worn on edge, on 13.5 per 100 MOTs.
Problems by part at 6 years
How many of every 100 MOTs found a fail, or an advisory or minor defect, in each area. A test with faults in two areas counts in both.
| Area | Fails | All cars | Advisories | All cars |
|---|---|---|---|---|
| Tyres | 7.2 | 5.6 | 24.7 | 24.3 |
| Suspension | 2.0 | 2.9 | 3.5 | 6.1 |
| Lights and electrics | 1.7 | 4.7 | 0.4 | 1.9 |
| Brakes | 1.4 | 3.5 | 5.1 | 16.9 |
| Exhaust, emissions and leaks | 1.0 | 1.3 | 0.1 | 1.2 |
| Windscreen, wipers and mirrors | 0.7 | 3.3 | 1.8 | 3.1 |
| Number plates and VIN | 0.4 | 0.2 | 0.6 | 1.0 |
| Road wheels | 0.4 | 0.2 | 1.3 | 0.6 |
| Body and structure | 0.1 | 0.8 | under 0.1 | 1.2 |
| Seat belts and airbags | 0.1 | 0.4 | under 0.1 | 0.2 |
| Steering | under 0.1 | 0.5 | 0.1 | 0.8 |
What testers fail most on the SLC at 6 years
| Item | Area | Per 100 MOTs | All cars | Typical repair (estimate) |
|---|---|---|---|---|
| Tyre with cords exposed | Tyres | 2.7 | 1.0 | £88 to £145 per tyre |
| Tyre condition: has a cut in excess of the requirements deep enough to reach the ply or cords | Tyres | 2.3 | 1.4 | £88 to £145 per tyre |
| Tyre tread below 1.6 mm | Tyres | 1.5 | 2.0 | £88 to £145 per tyre |
| Coil spring broken | Suspension | 0.9 | 1.0 | £64 to £236 per spring (rough guide) |
| Headlamp aim: too low | Lights and electrics | 0.6 | 0.8 | £16 to £39 per car (rough guide) |
| Suspension ball joint worn | Suspension | 0.5 | 0.4 | £75 to £237 per side (rough guide) |
| Tyre condition: has a tear, caused by separation or partial failure of its structure | Tyres | 0.5 | 0.4 | £88 to £145 per tyre |
| Anti-lock braking system: warning lamp indicates an ABS fault | Brakes | 0.5 | 0.1 | diagnosis from £59 (rough guide) |
| Tyre condition: has a bulge, caused by separation or partial failure of its structure | Tyres | 0.4 | 0.5 | £88 to £145 per tyre |
| Headlight aimed too high | Lights and electrics | 0.4 | 0.6 | £16 to £39 per car (rough guide) |
Early warnings: advisories and minor defects at 6 years
Advisories and minor defects are recorded, but the car still passes. Across all cars, a part with an advisory or minor defect failed at the next MOT 5.5 times in 100 (n=88,666,940 pairs of consecutive MOTs), against 0.3 times in 100 when the same part had none (n=12,936,860,350).
| Item | Area | Per 100 MOTs | All cars | If it needs replacing (estimate) |
|---|---|---|---|---|
| Tread depth: worn close to legal limit/worn on edge | Tyres | 13.5 | 14.3 | £88 to £145 per tyre |
| Tyre condition: slightly damaged/cracking or perishing | Tyres | 7.9 | 9.2 | £88 to £145 per tyre |
| Tyre condition: has a cut but not deep enough to reach the ply or cords | Tyres | 3.4 | 1.6 | £88 to £145 per tyre |
| Tread depth: worn close to legal limit/worn on edge | Tyres | 2.3 | 2.0 | £88 to £145 per tyre |
| Brake discs: worn, pitted or scored, but not seriously weakened | Brakes | 2.2 | 7.3 | £148 to £376 per axle (rough guide) |
| Brake pads: wearing thin | Brakes | 2.0 | 9.3 | £72 to £174 per axle (rough guide) |
| Wheel bearings: has slight play | Suspension | 1.9 | 0.1 | £103 to £276 per wheel (rough guide) |
| Tyre condition: slightly damaged | Tyres | 1.7 | 0.7 | £88 to £145 per tyre |
| Nail in tyre | Other | 1.5 | 2.0 | |
| Brake discs: worn, but not excessively | Brakes | 1.4 | 2.5 | £148 to £376 per axle (rough guide) |
Repair estimates are a guide for an independent garage: labour at the national median local garage rate (median £78 an hour from 65 garages, ONS price quotes) times estimated labour hours, plus a parts band. Labour hours and most parts bands are estimates, not quotes, and prices vary by model, engine and region. A warning light fault shows the cost of the diagnosis only.
How problems change with age
| Age | Tests (n) | Tyres | Suspension | Lights and electrics |
|---|---|---|---|---|
| 3 years | 1,838 | 4.9 | 0.4 | 1.6 |
| 4 years | 3,349 | 5.1 | 0.4 | 1.4 |
| 5 years | 6,599 | 6.8 | 0.9 | 1.5 |
| 6 years | 8,273 | 7.2 | 2.0 | 1.7 |
| 7 years | 7,266 | 6.9 | 3.6 | 2.0 |
| 8 years | 5,715 | 6.9 | 6.2 | 2.1 |
| 9 years | 2,266 | 6.8 | 5.4 | 2.3 |
Mileage
At 6 years, Mercedes-Benz SLC cars showing under 30,000 miles failed 9.6% of MOTs (n=4,752); the band that failed most, 30,000 to 60,000 miles, failed 17.1% (n=3,120). For pass and fail rates by age, see Mercedes-Benz SLC MOT fail rates.
What to check on a viewing
On the Mercedes-Benz SLC, testers most often record tyre with cords exposed; tyre condition: has a cut in excess of the requirements deep enough to reach the ply or cords; tyre tread below 1.6 mm. Look at these first, then the areas below.
Tyres
- Check the tread across the full width of all four tyres, and the spare if there is one.
- Look for cuts, bulges and cracking in the sidewalls.
- Wear on one edge only can point to worn suspension or the tracking being out.
Suspension
- Listen for knocks or clonks over speed bumps and rough roads on the test drive.
- Push down hard on each corner: the car should settle at once rather than keep bouncing.
- Look behind the wheels for broken or heavily rusted coil springs and split rubber bushes.
- Check that the car sits level and that no tyre is worn on one edge only.
Lights and electrics
- With someone outside, try every light: dipped and main beam, indicators, brake lights, fog lights and number plate lamps.
- Check that the warning lights come on with the ignition and go out once the engine runs.
- Look for misted, cracked or yellowed headlamp lenses.
Ask for the car's MOT history and service record: advisories that repeat from one year to the next show what has been left. GOV.UK MOT history.
Questions
What are the most common problems on the Mercedes-Benz SLC?
At 6 years, the age with the most MOT tests (8,273), the fail items testers record most often on the Mercedes-Benz SLC are tyre with cords exposed (2.7 per 100 MOTs), tyre condition: has a cut in excess of the requirements deep enough to reach the ply or cords (2.3 per 100 MOTs), tyre tread below 1.6 mm (1.5 per 100 MOTs). The most common advisories or minor defects are tread depth: worn close to legal limit/worn on edge (13.5) and tyre condition: slightly damaged/cracking or perishing (7.9).
Which parts of the Mercedes-Benz SLC fail more often than on other cars?
At 6 years: tyres (7.2 per 100 MOTs against 5.6 for all cars). Compared with 10,382,720 MOTs of all cars the same age.
Mercedes-Benz SLC problems by area
More on the Mercedes-Benz SLC
Other Mercedes-Benz models
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The all cars figures cover all class 4 vehicles (cars and light vans) tested at the same age.
Looking at a Mercedes-Benz SLC?
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Repair estimates: ONS consumer price quotes for local garage labour (09/2025 to 08/2026), the MOT inspection manual for defect wording, and estimated labour hours and parts bands. Not affiliated with or endorsed by ONS.
Source
Contains public sector information licensed under the Open Government Licence v3.0. Source: DVSA anonymised MOT test data, class 4 normal MOT tests, 2022 to 2025. MOT data updated 28 September 2026.
Not affiliated with or endorsed by DVSA. How we calculate these figures · Data sources