Porsche Cayman MOT Failures
An analysis of 20,623 real DVSA MOT tests on the Porsche Cayman — what fails, how often, and how that compares to every other car on UK roads. Generations covered: 987.1 (2005–2008), 987.2 (2009–2012), 981 (2013–2016), 718 (2016–2023).
Where the Porsche Cayman fails its MOT
The single biggest MOT failure point on the Porsche Cayman is tyre valve seriously damaged or misaligned — this model is 18 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 20,623 MOT tests, 1.57% of all Porsche Cayman tests recorded this as a failure.
Tyre failures indicate either poor maintenance or suspension geometry issues causing uneven wear. Check all four tyres for tread depth, sidewall damage, and uneven wear patterns.
Other notable weak points include track rod ends worn (24x the fleet average), emissions failure (8.1x the fleet average), brake pipes corroded (7.8x the fleet average), and suspension component damaged or corroded (6.5x the fleet average). These ratios compare the Porsche Cayman'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 7 categories: Tyres, Steering, Exhaust & Emissions, Brakes, Suspension and others. If you're inspecting a Porsche Cayman 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 Porsche Cayman'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 Porsche Cayman specifically, the DVSA data shows the most common failures at this mileage are track rod ends worn (24x the average) and tyre valve seriously damaged or misaligned (18x). brake pipes corroded (7.8x) and coil springs broken (7.3x) 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 Porsche Cayman specifically, the DVSA data shows the most common failures at this mileage are track rod ends worn (19x the average) and exhaust system damage (11x). tyre valve seriously damaged or misaligned (8.8x) and suspension component damaged or corroded (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 5.8x the fleet average.
The shift from track rod ends worn 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 Porsche Cayman specialists and owners flag most frequently, drawn from manufacturer technical bulletins, workshop data, and verified owner reports.
IMS bearing failure (987.1) Dangerous
The intermediate shaft (IMS) bearing supports the shaft that drives the camshafts on M96 and M97 flat-six engines. Affects 987.1.
Bore scoring (rare but possible on S) Dangerous
Cylinder wall scoring occurs when the bore surface becomes scratched or gouged, typically due to inadequate lubrication or debris in the oil system. Affects 987.1, 987.2.
Oil starvation on track use Dangerous
The 3.4L M97 engine suffers oil starvation under sustained high-G cornering due to inadequate oil pan design and pickup tube positioning. Affects 987.1.
Brake pipe corrosion Dangerous
MOT data shows Cayman models fail brake pipe corrosion tests at 7.7x the national fleet average, with 10,700 recorded failures across all generations. Affects 987.1, 987.2, 981; typical independent garage repair cost is £300–£600.
For the complete picture — including repair costs across independent, specialist, and dealer garages — see the full Porsche Cayman common problems breakdown.
What to check before buying a Porsche Cayman
Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Porsche Cayman:
Tyres — check for tyre valve seriously damaged or misaligned. Steering — check for track rod ends worn. Exhaust & Emissions — check for emissions failure. Brakes — check for brake pipes corroded.
Beyond the MOT items, ask specifically about ims bearing failure and bore scoring. These won't show up on a standard MOT but can be expensive to fix — 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 Porsche Cayman?
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Porsche Cayman MOT FAQs
What are the most common MOT failures on a Porsche Cayman?
Based on 20,623 DVSA MOT tests, the most common failure is tyre valve seriously damaged or misaligned — at 18x the national fleet average. Other frequent failures include track rod ends worn and emissions failure.
Is the Porsche Cayman reliable based on MOT data?
The Porsche Cayman has 8 MOT failure categories above the fleet average. Specialists also flag ims bearing failure 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 tyre valve seriously damaged or misaligned, track rod ends worn, emissions failure.
How do I check a Porsche Cayman'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.