Peugeot 508 MOT Failures
An analysis of 59,938 real DVSA MOT tests on the Peugeot 508 — what fails, how often, and how that compares to every other car on UK roads. Generations covered: Mk1 (2010–2018), Mk2 (2018–2022).
Where the Peugeot 508 fails its MOT
The single biggest MOT failure point on the Peugeot 508 is emissions failure — this model is 16 times more likely to fail on this item than the average car on UK roads. That makes it a significant weak point for anyone buying or owning this model. Across 59,938 MOT tests, 0.52% of all Peugeot 508 tests recorded this as a failure.
Exhaust and emissions failures often point to catalytic converter degradation, lambda sensor faults, or — in diesel models — DPF problems. These can be expensive to fix and will cause an immediate MOT failure.
Other notable weak points include stop lamp with a multiple light source up to 1/... (16x the fleet average), transmission shaft constant velocity joint boot... (14x the fleet average), reflector defective or damaged by up to 50% of ... (11x the fleet average), and tyre seriously damaged (10x the fleet average). These ratios compare the Peugeot 508's failure rate on each item against the national average for all cars tested — a ratio of 10x means this model fails ten times more often than a typical car.
The failures span 6 categories: Exhaust & Emissions, Lights & Electrics, Bodywork, Tyres, Wipers & Windscreen and others. If you're inspecting a Peugeot 508 before purchase, these are the areas to focus on — and if any have been flagged as advisories on a previous MOT, they're likely to become failures in the near future.
How failures change with mileage
The Peugeot 508's weak points shift as the car covers more miles. Understanding these patterns helps you know what to expect — and what to budget for — at each stage of ownership.
Under 60,000 miles
At this mileage, most failures are either design-related or caused by age rather than wear. Components like bushes and drop links may not have been replaced yet, and original-fit parts can deteriorate even on low-mileage cars that spend a lot of time sitting.
For the Peugeot 508 specifically, the DVSA data shows the most common failures at this mileage are suspension pin, bush or joint (21x the average) and stop lamp with a multiple light source up to 1/... (16x). emissions failure (16x) and transmission shaft constant velocity joint boot... (14x) also appear frequently.
60,000 to 100,000 miles
This is where routine wear items start to show up. Brake components, tyres, and exhaust parts have done serious work by this point. Cars that have been well serviced will show fewer of these failures — this mileage band is where good maintenance really separates the well-kept from the neglected.
For the Peugeot 508 specifically, the DVSA data shows the most common failures at this mileage are emissions failure (9.7x the average) and headlight fault (8.1x). reflector defective or damaged by up to 50% of ... (6.7x) and wiper fault (6.3x) also appear frequently.
Over 100,000 miles
High-mileage cars accumulate failures across multiple systems. The key question isn't whether things will need doing — they will — but whether the car has been maintained well enough to keep on top of them. Look for a consistent service history and recent MOT passes with minimal advisories.
The standout failure at this mileage is emissions failure at 5.1x the fleet average.
The shift from suspension pin, bush or joint at lower mileages to emissions failure at higher mileages is typical — early failures tend to be design or factory-related, while high-mileage failures reflect accumulated mechanical wear. A car that's been well maintained will usually dodge the worst of both.
Known issues beyond the MOT
An MOT only tests roadworthiness at a single point in time — it won't catch developing faults, intermittent problems, or issues that haven't yet reached the failure threshold. These are the issues that Peugeot 508 specialists and owners flag most frequently, drawn from manufacturer technical bulletins, workshop data, and verified owner reports.
Timing chain issues (Mk1) Major
The EP6 1.6 THP engine uses a single-row timing chain that stretches prematurely due to inadequate oil change intervals and design limitations. Affects Mk1; typical independent garage repair cost is £2,000–£3,000.
DPF blockage and regeneration issues (Mk1) Major
The diesel particulate filter (DPF) on DV6 1.6 HDi and DW10 2.0 HDi engines blocks with soot when used primarily for short journeys or stop-start driving. Affects Mk1; typical independent garage repair cost is £200–£400.
Turbocharger failure (Mk1) Major
The DW12 2.2 HDi engine uses a variable geometry turbocharger that fails due to carbon build-up in the variable vane mechanism and bearing wear from oil contamination. Affects Mk1; typical independent garage repair cost is £1,200–£2,000.
CV joint boot deterioration
The CV joint boots on diesel variants deteriorate at 64.3x the fleet average rate, with the highest failure rate occurring unusually early at 20,000-40,000 miles. Affects Mk1; typical independent garage repair cost is £80–£150.
For the complete picture — including repair costs across independent, specialist, and dealer garages — see the full Peugeot 508 common problems breakdown.
What to check before buying a Peugeot 508
Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Peugeot 508:
Exhaust & Emissions — check for emissions failure. Lights & Electrics — check for stop lamp with a multiple light source up to 1/..., reflector defective or damaged by up to 50% of ..., headlight fault. Bodywork — check for transmission shaft constant velocity joint boot....
Beyond the MOT items, ask specifically about timing chain issues and dpf blockage and regeneration issues. These won't show up on a standard MOT but can be expensive to fix — repairs start from £2,000. A specialist pre-purchase inspection is worth the investment on this model.
Always check the car's full MOT history for patterns — recurring advisories often become failures within 12 months. And verify the service history to confirm maintenance has been kept up to schedule. Enter any reg into our free car check to see the complete picture.
Looking at a specific Peugeot 508?
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Peugeot 508 MOT FAQs
What are the most common MOT failures on a Peugeot 508?
Based on 59,938 DVSA MOT tests, the most common failure is emissions failure — at 16x the national fleet average. Other frequent failures include stop lamp with a multiple light source up to 1/... and transmission shaft constant velocity joint boot....
Is the Peugeot 508 reliable based on MOT data?
The Peugeot 508 has 11 MOT failure categories above the fleet average. Specialists also flag timing chain issues as a concern. A pre-purchase inspection and service history check are recommended.
What MOT failures should I expect at high mileage?
The most common high-mileage failures include emissions failure, stop lamp with a multiple light source up to 1/..., transmission shaft constant velocity joint boot....
How do I check a Peugeot 508's MOT history?
Enter the registration number into our free car check above. You'll see every MOT test result, advisories and failures, mileage readings, write-off status, and finance checks.
MOT failure data sourced from DVSA bulk test records via data.gov.uk. Ratios compare this model's failure rate against the national fleet average. Known issues sourced from manufacturer bulletins, specialist workshops, and verified owner reports.