1989 Mercedes-Benz S-Class — MOT failures & pass rate
267 MOT tests on the 1989 Mercedes-Benz S-Class are in this dataset, and 85.4% of them passed. That is 3.1 percentage points better than executive cars of a similar age, which fail at 17.7%. Failures cluster in suspension, brakes and body, structure & corrosion.
What the MOT record shows
No single area dominates — suspension (7.9%) and brakes (6.4%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are ball joint dust cover, service brake performance and component mounting prescribed areas — ball joint dust cover alone was recorded 18 times.
Mileage matters less than usual here: the 1989 S-Class fails 18.8% of the time in the 60-90k band and 17.9% at 150k+, a spread of only 0.9 points.
Advisories point at the next bill rather than this one: suspension was flagged on 22.5% of tests without failing them.
The trend is worsening — 12.9% of tests failed in 2021 against 19.0% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 7.9% | 21 |
| 2 | Brakes | 6.4% | 17 |
| 3 | Body, structure & corrosion | 6.0% | 16 |
| 4 | Lighting & signalling | 4.9% | 13 |
| 5 | Visibility | 3.4% | 9 |
| 6 | Steering | 3.0% | 8 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Ball joint dust cover | 18 |
| 2 | Service brake performance | 12 |
| 3 | Component mounting prescribed areas | 9 |
| 4 | Exhaust system | 8 |
| 5 | Rigid brake pipes | 7 |
| 6 | Flexible brake hoses | 7 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 22.5% | 60 |
| 2 | Brakes | 16.5% | 44 |
| 3 | Emissions & environmental | 12.4% | 33 |
| 4 | Tyres | 9.7% | 26 |
| 5 | Body, structure & corrosion | 9.7% | 26 |
| 6 | Steering | 8.6% | 23 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 60-90k | 32 | 18.8% |
| 90-120k | 75 | 9.3% |
| 120-150k | 83 | 18.1% |
| 150k+ | 56 | 17.9% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 62 | 12.9% |
| 2022 | 52 | 15.4% |
| 2023 | 51 | 13.7% |
| 2024 | 44 | 11.4% |
| 2025 | 58 | 19.0% |
What to check before buying a 1989 S-Class
On a 1989 S-Class, suspension is what the MOT record says goes wrong most — it appeared in 7.9% of tests. Check these areas before you commit.
- Suspension (7.9% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
- Brakes (6.4% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
- Body, structure & corrosion (6.0% of tests): The one to take seriously on older cars — corrosion to structural areas can be costly and is an MOT failure. Typical repair: £200–£1,500+.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
How many 1989 Mercedes-Benz S-Classs pass their MOT?
85.4% of the 267 1989 Mercedes-Benz S-Class MOT tests in this dataset passed — a 14.6% fail rate.
What is the most common MOT failure on a 1989 Mercedes-Benz S-Class?
Suspension, recorded in 7.9% of tests, followed by brakes (6.4%).
Does the 1989 S-Class get worse with mileage?
Its MOT fail rate rises from 18.8% in the 60-90k band to 17.9% in the 150k+ band.
Methodology & source. Based on 267 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.