1979 Mercedes Sl 350 MOT Pass Rate
Pass rate for Sl 350 models manufactured in 1979, based on 271 real MOT test results.
Data from official DVSA MOT testing records
This page shows all Sl 350 cars tested in 1979. Want to see how cars built in 1979 hold up over time?
View 1979 Mercedes Sl 350 vintage page → (68.8% current pass rate)1979 Mercedes Sl 350 MOT Analysis
The 1979 Mercedes Sl 350 has an MOT pass rate of 69.0% based on 271 tests — slightly above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 92,030 miles on the odometer. With a 31.0% failure rate, the 1979 Sl 350 is rated as "Good" for MOT reliability.
The leading cause of MOT failure for the 1979 Mercedes Sl 350 is Noise, emissions and leaks, responsible for 1.1% of failures. Emissions failures occur when exhaust gases exceed legal limits for carbon monoxide (CO), hydrocarbons (HC), or particulate matter (diesel). Common causes include faulty oxygen sensors, clogged catalytic converters, or DPF issues on diesel vehicles. Typical repair costs range from £100–1,000+. Body, chassis, structure is the second most common issue at 0.7%. Brakes follows at 0.7%.
Top failures specific to 1979 models only. The overall Sl 350 page may show different rankings.
What Fails Most
What Fails on This Car?
Click a category to see specific failure items.
View as table
| Rank | Failure Category | Rate (%) | Count |
|---|---|---|---|
| 1 | Noise, Emissions And Leaks | 1.1% | 3 |
| 2 | Body, Chassis, Structure | 0.7% | 2 |
| 3 | Brakes | 0.7% | 2 |
| 4 | Lamps, Reflectors And Electrical Equipment | 0.4% | 1 |
| 5 | Seat Belts And Supplementary Restraint Systems | 0.4% | 1 |
Failures per 10,000 Miles
avg. 92,030 miFor every 10,000 miles driven, this shows what percentage of MOT tests fail for each category. This accounts for how far cars are actually driven, not just raw pass/fail counts.
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| Category | Rate / 10K mi | Raw % | Count |
|---|---|---|---|
| Noise, emissions and leaks | 0.12 | 1.1% | 3 |
| Body & Structure | 0.08 | 0.7% | 2 |
| Brakes | 0.08 | 0.7% | 2 |
| Lamps & Electrical | 0.04 | 0.4% | 1 |
| Seat Belts | 0.04 | 0.4% | 1 |
Mileage Statistics
Mileage-adjusted failure rate — accounts for how much this model year is typically driven.
About This Data
The 1979 Mercedes Sl 350 has an MOT pass rate of 69.0% based on 271 tests — slightly above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 92,030 miles on the odometer. With a 31.0% failure rate, the 1979 Sl 350 is rated as "Good" for MOT reliability.
If you own or are considering buying a 1979 Mercedes Sl 350, you can expect reliable MOT performance overall. Before your MOT, pay particular attention to noise, emissions and leaks: If the engine management light is on, get it diagnosed before the MOT. For diesel cars, ensure the DPF has completed a regeneration cycle. Regular servicing and using premium fuel before the test can help. With an average mileage of 92,030 miles, these vehicles are in the higher-mileage bracket where wear-related failures become more common.
Noise, emissions and leaks — 1.1% of failures
Noise, emissions and leaks issues account for 1.1% of MOT failures on 1979 Mercedes Sl 350 models. Emissions failures occur when exhaust gases exceed legal limits for carbon monoxide (CO), hydrocarbons (HC), or particulate matter (diesel). Common causes include faulty oxygen sensors, clogged catalytic converters, or DPF issues on diesel vehicles. Typical repair costs: £100–1,000+. Pre-MOT check: If the engine management light is on, get it diagnosed before the MOT. For diesel cars, ensure the DPF has completed a regeneration cycle. Regular servicing and using premium fuel before the test can help.
Body, chassis, structure — 0.7% of failures
Body, chassis, structure issues account for 0.7% of MOT failures on 1979 Mercedes Sl 350 models. Body and structure failures include excessive corrosion, sharp edges, loose panels, and damage to the vehicle frame. Rust is the primary concern, especially on older vehicles or those exposed to road salt. Typical repair costs: £100–500+. Pre-MOT check: Inspect sills, wheel arches, door bottoms, and the chassis for rust. Surface rust is acceptable but structural corrosion or holes will fail. Check that all doors, bonnet, and boot close securely.
Brakes — 0.7% of failures
Brakes issues account for 0.7% of MOT failures on 1979 Mercedes Sl 350 models. Brake-related failures include worn brake pads, corroded brake discs, leaking brake lines, and faulty brake servos. These are safety-critical components — any brake deficiency will result in an MOT fail. Typical repair costs: £150–400. Pre-MOT check: Listen for squealing or grinding noises. Check brake pedal feel — if it feels spongy or goes to the floor, have the system inspected immediately. Look at brake pad thickness through the wheel spokes (minimum 3mm).
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.