BMW 420d Gran Coupe M Sport Auto (2017)
2017 BMW 420d Gran Coupe M Sport Auto
CarHunch analysed 442 real MOT records for the 2017 BMW 420d Gran Coupe M Sport Auto. This breakdown of actual test outcomes — pass rates, defect profiles, mileage data — isn't published anywhere else.
This 2017 BMW 420D is a genuine reliability concern: it passes its MOT first time in just 58.8% of cases, significantly below the UK average of 80%, and that underperformance is consistent across the diesel variants that make up virtually all of this cohort. The good news is that dangerous defects are absent from the data, so what's failing isn't safety-critical—it's typically the small niggles that cost money to fix.
At 70,000 miles on average, these cars are showing relatively low mileage for their age, yet they're still averaging 0.12 failures per vehicle, which points to premature wear or design weaknesses rather than hard use. Before buying, have a pre-purchase inspection focus on the cooling system, electronics, and suspension components, as these are the typical failure points on high-spec BMW diesels of this generation.
What to check before buying a 2017 BMW 420d Gran Coupe M Sport Auto
Practical pre-purchase checks for this age and model.
- 📋 Check the full MOT history. Look for recurring advisories — slow-building issues like corrosion or brake wear patterns show up years before they become failures. Enter the reg below for a full AI analysis.
- 🔍 Inspect for corrosion in person. Brake pipes, sills, subframes, and chassis legs. Surface rust is normal at this age; structural rust is a serious problem that's expensive to fix and can fail an MOT.
- 🛞 Check tyres and brakes. The most common advisory items at this age. Budget for replacement if they're near the limit — factor this into your offer price.
- 📄 Run an HPI check. The MOT history won't show outstanding finance, insurance write-offs, or stolen status — an HPI check will.
Before you buy a BMW 420d Gran Coupe M Sport Auto
MOT history is one piece of the puzzle. These checks can reveal what CarHunch can't.
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Pass Rate by Fuel Type
| Fuel type | Vehicles | Pass rate | Avg failures |
|---|---|---|---|
| Diesel (99%) | 439 | 58.6% | 0.12 |
| Gas Bi-Fuel (1%) | 3 | 91.7% | 0.33 |
Mileage Distribution
Most 2017 BMW 420d Gran Coupe M Sport Auto vehicles sit in the blue band. If the car you're looking at is outside it, it's either unusually low or high mileage for its age.
Half of all 2017 BMW 420d Gran Coupe M Sport Auto vehicles fall between 55,203 and 84,497 miles.
2017 BMW 420d Gran Coupe M Sport Auto — Still on the Road
Strong survival — 150 vehicles still getting MOTs in 2025, 88% of the peak.
Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2021–2025.
MOT History Averages
Found a specific BMW 420d Gran Coupe M Sport Auto?
Enter the reg to see its individual MOT history, AI Hunches, and how it compares to this cohort.