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Porsche Cayman (987) 2.7 / 2.9 / 3.4buyer's guide

2005–2012

The faults this model is known for, what they tend to cost in the UK, and what a service history has to show before any of them counts as covered. Researched from the sources shown, and open to correction.

If none of it were documented

£10,450–£23,000

Across 11 costed items.

This is a ceiling, not a forecast. A report on a specific car counts only the items its paperwork does not already cover - a folder showing the clutch done last year removes that line entirely.

Known faults

IMS (intermediate shaft) bearing

£1,500–£2,500

The bearing supporting the shaft that drives the camshafts can fail and take the engine with it. On the 987 the risk is concentrated in the earliest cars: from the 2006 model year Porsche fitted a larger bearing that cannot be replaced without splitting the engine, and failures on it are rare. A 2005 car may have had the retrofit; a car of any year with a clutch invoice that mentions the IMS has answered the question.

A retrofit on a 2005 car is quoted around £1,500 to £2,500 in the UK, normally done with the clutch because the gearbox has to come out either way. A failure that reaches the engine is a rebuild, well into five figures.

Typically bites

Not mileage-driven in any reliable way. Treated as insurance on the 2005 cars that can take a retrofit, and as a low-probability risk on 2006-2008 cars that cannot.

Verified against 3 published sources.

Cylinder bore scoring

£5,000–£12,000

The piston wears through the cylinder wall, letting oil past into the combustion chamber. The car burns oil, ticks when cold and smokes, and the fix is the engine apart. Specialists put it at roughly one pre-DFI car in twenty, concentrated on the 3.4 S and more on the Cayman than the Boxster; it is rare on the 2.7. There is no preventative fix, only a borescope inspection, which is the cheapest money anybody spends on one of these cars.

A borescope inspection is about £100 to £250. A repair means resleeving with new pistons, quoted from around £5,000 for the cylinder work and well beyond that once the engine is out and rebuilt.

Typically bites

Reported across the 987.1 range with no reliable mileage. Short journeys and long oil intervals are both implicated, which is why the service record is part of the answer.

Verified against 3 published sources.

Rear main seal (RMS)

£750–£1,100

The seal between engine and gearbox weeps oil. A nuisance rather than a catastrophe, but the gearbox has to come out to reach it, so it is done with the clutch and, on a 2005 car, with the IMS retrofit. A clutch invoice that mentions neither has paid for the access and used it once.

Little on its own; the labour is the clutch job. A clutch at a UK independent is around £750 to £1,000, and the seal adds a small amount to that.

Typically bites

Age- and use-related. Oil misting on the bellhousing seam is the sign.

Verified against 2 published sources.

High-pressure fuel pump

£800–£1,400

A batch of Bosch pumps on early direct-injection cars failed, putting the car into reduced power with a warning light. Porsche ran a service campaign (WB09) fitting a revised pump. The question on a 2009-2010 car is whether the campaign was done, which the service book or a dealer history check will show.

A replacement pump is around £800 in parts alone and is awkward to reach, so a job outside the campaign runs to four figures.

Typically bites

A production batch problem rather than wear: mostly 2009 and early 2010 cars, and mostly already dealt with.

Verified against 2 published sources.

Carbon build-up on the inlet valves

£300–£700

Direct injection sprays fuel into the cylinder rather than over the back of the inlet valves, so nothing washes them and deposits build up. The signs are a rough idle, hesitation low in the rev range and, eventually, misfires. Cars used for short, slow journeys build it fastest; a car that is driven properly builds far less.

A walnut-blast or chemical clean at a specialist is in the mid hundreds.

Typically bites

Use-dependent rather than fixed. Worst on low-mileage cars that have done many short trips.

Verified against 2 published sources.

Air-oil separator

£250–£600

A failed separator lets oil into the intake, producing clouds of white smoke on start-up and a car that looks catastrophically unwell while being cheap to fix. Worth knowing precisely because the symptom is so alarming.

A few hundred pounds fitted at an independent.

Typically bites

Wear-related, commonly once the car passes ten years old.

Verified against 2 published sources.

Water pump, coolant pipes and expansion tank

£400–£1,000

The water pump has a plastic impeller that sheds blades, the plastic expansion tank goes brittle and cracks, and on the 987.1 the seals on the front coolant pipes harden and weep. All three are age and heat items on a mid-engined car that runs hot, and on a 987.1 an overheat is not a self-contained event: it is one of the things that brings bore scoring on.

Each is a routine independent job in the low hundreds; a pump, tank and pipe seals done together is a mid-hundreds to low-four-figure job.

Typically bites

Age-driven. The PistonHeads guide puts water pumps at as little as 40,000 miles; most cars of this age are on a second one.

Verified against 2 published sources.

Radiators and air-conditioning condensers

£500–£1,500

Both sit low in the front bumper behind open vents and fill with leaves and road grit, which holds moisture against them until they corrode through. A clogged expansion tank vent makes it worse. Every specialist guide names it, and it is the item a low-mileage garaged car is least likely to have escaped, because it is about years rather than miles.

Condensers and radiators together are a four-figure job at a specialist; a single condenser is in the mid hundreds.

Typically bites

Age-driven. Specialists say five to eight years from new, so almost every surviving car has either had them or needs them.

Verified against 3 published sources.

Coil springs

£250–£600

Broken coil springs are common enough that suspension is the second most frequent reason a 987 fails an MOT. The car sits unevenly or knocks over rough roads. Cheap in isolation, and a sign of the age of everything else underneath.

A pair of springs fitted at an independent is in the low to mid hundreds.

Typically bites

Age- and corrosion-driven rather than mileage-driven.

Verified against 2 published sources.

Suspension arms and bushes

£400–£1,000

The lower arm bushes delaminate and the trailing arm joints wear, felt as creaking, knocking over bumps and steering that loses its precision. The tell is tyre wear on the inside edge, which is hard to see on the rears and is the reason so many 987s are sold on tyres that are worn out on the side the buyer cannot see.

Bushes are quoted at about £200 each; a pair of complete lower arms with alignment is in the mid hundreds to about £1,000.

Typically bites

Reported from about 30,000 miles, and universal on cars of this age on original parts.

Verified against 2 published sources.

Ignition coil packs

£300–£600

The coils crack with heat and the car misfires, stutters and throws a warning light. Specialists name the 987 in particular for it, and replace all six at once because the access is the same and doing one at a time is the expensive way.

A full set of six coils and plugs at an independent is in the mid hundreds.

Typically bites

Heat-cycle driven rather than mileage-driven.

Verified against 2 published sources.

Service interval

Every 20,000 miles or 24 months, whichever comes first.

The factory interval is two years or 20,000 miles. Specialists advise an annual oil change regardless, and on a 987.1 that is not fussiness: oil condition is implicated in bore scoring, so a folder showing two-year gaps between oil changes is itself a finding. The service campaign for the fuel pump (WB09) belongs in the book of any 2009-2010 car.

The interval is here so a report can do arithmetic rather than form an opinion: last recorded service, current mileage, today's date. Whether a car is overdue is a sum, and sums should not be able to hallucinate.

What to check on the day

Written to be read standing next to the car, with the folder open.

  1. Establish the generation before anything else. A 2009 or later car has a different engine and none of the IMS, bore scoring or rear main seal questions.

  2. On a 987.1, ask directly whether it has been borescoped, and ask to see the report rather than accepting the answer. Cold start it and watch the exhaust from outside for the first thirty seconds.

  3. Crouch at the front vents with a torch: leaves packed against the condensers mean they have not been cleared, and corrosion on the cores is visible.

  4. Look at the inside edges of all four tyres. Inside-edge wear is the bush and alignment problem showing itself.

  5. Drive it over a rough road with the radio off and listen for knocks and creaks from the front.

  6. On a 987.2, listen for an uneven idle and feel for hesitation low in the revs, which point at carbon.

  7. On a Boxster, operate the roof twice and check behind the seats for damp: blocked drains put water near the electronics.

What this research does not know

  • Bore scoring rates come from specialist commentary rather than any published sample, and the repair band is the widest in this profile because it depends entirely on what the strip reveals.
  • Several sources price in euros or dollars. GBP bands here are UK independent specialist rates rather than conversions.
  • Engine capacities are as DVSA records them, so the 987.2 3.4 appears as 3,387cc here, which is also the 987.1 3.4 capacity; the generation field on each item is what tells them apart.
  • The 987 ran to 2012 and the 981 arrived that year with different recorded capacities (2,706cc and 3,436cc), so the two generations do not collide in the cache.
  • The Boxster Spyder and Cayman R share this profile. Their specific items (the Spyder roof, the lightweight parts) are not costed here.

Last reviewed on 29 September 2026. Cost bands are indicative UK independent-specialist rates, not quotes.

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