The 2007 Cayman is actually a 987.1 generation car, not a 718 (which didn't arrive until 2017). The 2.7L M97 flat-six is the real concern here—infamous for intermediate shaft (IMS) bearing failures that can grenade the engine without warning, plus cylinder scoring issues that require complete rebuilds.
IMS Bearing Failure (Catastrophic Engine Damage)
Occasional · high severityTypical onset: 40,000-80,000 mi
Symptoms: metallic debris in oil filter during changes, sudden loss of oil pressure, catastrophic engine noise then seizure, often NO warning symptoms until failure
Fix: Preventive IMS retrofit requires dropping transmission and clutch replacement while you're in there (8-12 hours labor). If it fails, you're looking at complete engine rebuild or replacement (40-60 hours). Many owners do preventive replacement around 50k-60k miles.
Estimated cost: $2,500-4,000 preventive retrofit; $15,000-25,000 post-failure engine rebuild
Cylinder Bore Scoring (Lokasil Cylinder Wall Failure)
Occasional · high severityTypical onset: 60,000-100,000 mi
Symptoms: excessive oil consumption (quart every 500-1000 miles), blue smoke on cold start, rough idle when warm, loss of compression on specific cylinders
Fix: Requires complete engine disassembly and either cylinder sleeving or replacement with factory Nickasil block. This is a 45-60 hour job including machine work. Some shops offer bore-scope inspection ($300-500) to catch early.
Estimated cost: $18,000-28,000 for full repair with upgraded cylinders
Rear Main Seal (RMS) Oil Leak
Common · medium severityTypical onset: 50,000-90,000 mi
Symptoms: oil spots on driveway centered under engine/trans bell housing, oil visible on clutch housing or transmission bellhousing, burning oil smell after spirited driving
Fix: Requires transmission and clutch removal to access seal (8-10 hours). Smart owners combine this with IMS bearing retrofit and clutch replacement to avoid paying transmission-drop labor twice.
Estimated cost: $1,800-3,200 (seal alone); $4,000-6,500 if bundling IMS and clutch
Coolant Expansion Tank Cracking
Common · medium severityTypical onset: 70,000-120,000 mi
Symptoms: coolant smell in cabin or under hood, visible coolant weeping from tank seams, low coolant warning light, coolant visible on engine undertray
Fix: Plastic tank becomes brittle and cracks at mounting tabs or seams. Replacement is straightforward (1.5-2 hours) but requires proper bleeding procedure. Always replace with upgraded aluminum tank if budget allows.
Estimated cost: $400-700 with OEM plastic; $800-1,200 with upgraded aluminum tank
Transmission/Engine Mount Failure
Common · low severityTypical onset: 60,000-100,000 mi
Symptoms: excessive drivetrain clunk on throttle tip-in or shifting, vibration at idle in gear, visible tearing or fluid leaking from mounts
Fix: Hydraulic mounts fail and leak fluid. Transmission mount (2-3 hours) and engine mounts (3-4 hours each side) are common replacements. Do both sides simultaneously to avoid repeat labor charges.
Estimated cost: $800-1,500 per mount; $2,500-4,000 for all mounts
Fuel Filter Housing Corrosion and Leaks
Occasional · medium severityTypical onset: 80,000-120,000 mi
Symptoms: fuel smell in cabin or near fuel tank, difficulty starting when tank below half, visible fuel weeping from filter area, check engine light with fuel pressure codes
Fix: Filter housing and lines corrode where they pass through chassis. Access requires removing undertray and sometimes fuel tank (3-5 hours depending on extent). This is a fire risk if ignored.
Estimated cost: $600-1,200 depending on line replacement extent
Buy only if IMS bearing has been retrofitted and bore-scope confirms healthy cylinders—otherwise you're gambling with a $20k engine rebuild at any moment, but a sorted example is one of the best-driving cars of the era.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.