Mercedes SL Reliability: Common Problems and Years to Avoid
What the Mercedes SL fails its MOT on, with rough repair costs, and how each model year's MOT pass rate compares with other cars of the same age. Based on 50,180 MOT tests across 30 model years (DVSA data for tests carried out in 2024, retests included).
Segment: premium performance | Fuel: Petrol
89%
Mercedes SL pass rate
87%
Mercedes average
82%
All-model average
The Mercedes SL has an average MOT pass rate of 89%, which is 2 points above the Mercedes average and 7 points above the average across all models in our data. Newer Mercedes SLs pass their MOT more often than older ones, by 4 percentage points on average, which is mostly down to age and wear.
Check Your Mercedes SL's MOT History
Enter your reg plate to see the specific issues found on your car, plus a health score and running cost estimate.
What the Mercedes SL Fails Its MOT On
Of the 3,504 MOT tests on the Mercedes SL that failed at the first attempt in 2025, the share that failed on each part of the test, next to the share for all cars and vans of the same ages. A test that failed on two areas counts in both.
Suspension
30%Cars and vans the same age: 36% · Typical repair £150-£600
Lights and electrics
28%Cars and vans the same age: 46% (the SL fails on this less often) · Typical repair £15-£200
Tyres
24%Cars and vans the same age: 15% (the SL fails on this more often) · Typical repair £50-£300
Brakes
20%Cars and vans the same age: 28% (the SL fails on this less often) · Typical repair £80-£450
Windscreen, wipers and mirrors
13%Cars and vans the same age: 17% (the SL fails on this less often) · Typical repair £10-£350
The 3 single faults it failed on most
- Coil spring: fractured or broken (7.1% of failed tests, suspension)
- Suspension arm ball joint excessively worn (6.9% of failed tests, suspension)
- Tyre has ply or cords exposed (6.4% of failed tests, tyres)
Source: CarCostCheck analysis of DVSA anonymised MOT test results and failure items for 2025: first attempt at each MOT, fail and pass-after-repair defects, DVSA's defect categories (names shortened). Repair costs are rough UK ranges, not quotes. Method and national figures: MOT failure reasons 2025.
Buying a Mercedes SL? Check it first
See that car's own MOT history and mileage free, then check it for outstanding finance, an insurance write-off and a stolen record before you pay.
History check £4.99, one-off. No subscription.
Mercedes SL Years to Avoid
Every car in the 2024 MOT data was tested at the same age as the other cars first registered that year, so each SL year is compared with all cars from the same year. Years with 1,000+ tests that were at least three years old are included.
Failed more often than cars their age
No year passed 3 or more points less often than other cars of the same age.
A lower pass rate means that year failed its MOT more often in 2024; it does not mean every car from that year is bad. Old cars still on the road are often the best-kept ones, which can lift the pass rates of the oldest years. How a car has been looked after matters more, so check the MOT history of the car you are looking at.
Mercedes SL Reliability by Year
MOT pass rate for each model year, from DVSA data for tests carried out in 2024 (retests included). Newer cars usually pass more often simply because they are younger. All Cars is the pass rate of every car first registered that year, with the gap in points. Highest and lowest are marked among years with 100+ tests that were at least three years old when tested. Fuel and engine size are a guide only.
| Year | Fuel | Engine | Pass Rate | Fail Rate | All Cars |
|---|---|---|---|---|---|
| 2019 | Petrol | 4.7L | 97% | 3% | - |
| 2018 | Petrol | 4.7L | 93% | 7% | 89% (+4) |
| 2017 | Petrol | 4.7L | 94% | 5% | 87% (+7) |
| 2016 | Petrol | 4.7L | 95% | 5% | 86% (+9) |
| 2015 | Petrol | 4.7L | 92% | 7% | 84% (+8) |
| 2014 | Petrol | 4.7L | 92% | 8% | 82% (+10) |
| 2013 | Petrol | 4.7L | 89% | 10% | 80% (+9) |
| 2012 | Petrol | 4.7L | 90% | 9% | 79% (+11) |
| 2011 | Petrol | 6.2L | 92% | 8% | - |
| 2010 | Petrol | 6.2L | 88% | 11% | - |
| 2009 | Petrol | 5.5L | 87% | 12% | 75% (+12) |
| 2008 | Petrol | 5.5L | 90% | 10% | 74% (+16) |
| 2007 | Petrol | 5.5L | 88% | 11% | 73% (+15) |
| 2006 | Petrol | 5.4L | 87% | 13% | 73% (+14) |
| 2005 | Petrol | 3.7L | 88% | 11% | 73% (+15) |
| 2004 | Petrol | 5.5L | 88% | 11% | 72% (+16) |
| 2003 | Petrol | 5.0L | 86% | 13% | 72% (+14) |
| 2002 | Petrol | 5.0L | 88% | 12% | 73% (+15) |
| 2001 | Petrol | 3.2L | 90% | 9% | - |
| 2000 | Petrol | 3.2L | 86% | 13% | - |
| 1999 | Petrol | 5.0L | 87% | 13% | 75% (+12) |
| 1998 | Petrol | 5.0L | 86% | 13% | 76% (+10) |
| 1997 | Petrol | 5.0L | 87% | 12% | 76% (+11) |
| 1996 | Petrol | 2.8L | 88% | 11% | 77% (+11) |
| 1995 | Petrol | 5.0L | 85% | 14% | 77% (+8) |
| 1994 | Petrol | 5.0L | 88% | 11% | 78% (+10) |
| 1993 | Petrol | 3.0L | 88% | 8% | - |
| 1992 | Petrol | 3.0L | 87% | 13% | - |
| 1991 | Petrol | 5.0L | 86% | 14% | - |
| 1990 | Petrol | 3.0L | 81% | 19% | - |
Mercedes SL Running Costs
Want to know the full annual running costs for the Mercedes SL? Including fuel, road tax, the MOT and predicted repairs based on MOT pass rates, plus an estimated insurance group.
View Mercedes SL Running CostsCar history check for £4.99
Finance, stolen and write-off checks
Outstanding finance with the lender's details, stolen, write-off and keeper changes. One payment, no subscription.
Comparing checks first? See the cheapest car check in the UK and the best car check providers compared.
Mercedes SL FAQ
What are the most common Mercedes SL problems?
In 2025, MOT tests on the Mercedes SL that failed at the first attempt most often failed on suspension (30% of the 3,504 failed tests), lights and electrics (28%) and tyres (24%). The single most common fault was "Coil spring: fractured or broken" (7.1%). Across 50,180 MOT tests (DVSA MOT data for tests in 2024, retests included), 89% ended in a pass.
Is the Mercedes SL reliable?
The Mercedes SL has an average MOT pass rate of 89%, from 50,180 MOT tests (DVSA MOT data for tests in 2024, retests included). Comparing each model year with all cars first registered the same year, so that age is allowed for, it passed 12 points more often on average, a better than average result for its age.
Which Mercedes SL years should I avoid?
No Mercedes SL year with 1,000+ tests passed 3 or more points less often than all cars first registered the same year (DVSA MOT data for tests in 2024, retests included). The years that passed most often for their age were the 2004 (88% of 4,036 tests passed, against 72% for all 2004 cars), the 2008 (90% of 1,940 tests passed, against 74% for all 2008 cars) and the 2005 (88% of 2,430 tests passed, against 73% for all 2005 cars). A year's pass rate does not tell you about one car, so check the MOT history of the car you are buying.
How much does it cost to fix common Mercedes SL faults?
As a rough guide, brake work on a Mercedes SL typically costs £80-£450 and suspension repairs £150-£600, while exhaust and emissions fixes can cost £80-£800. Lighting and wiper fixes are usually under £200.
Check a Specific Mercedes SL
Enter any reg plate to see the exact MOT history, defects found, health score, and running cost estimate for that specific car.
Other Mercedes Models
Common problems pages for other Mercedes models