The 2009 Cayman S (987.2 generation) with the 3.4L MA1.21 flat-six is generally solid, but suffers from intermediate shaft bearing failures, bore scoring risk, and typical Porsche rubber/mount degradation as they age past 80k miles.
Intermediate Shaft Bearing (IMS) Failure
Occasional · high severityTypical onset: 60,000-120,000 mi
Symptoms: metallic rattling from engine at startup or idle, metal shavings in oil filter during changes, catastrophic engine failure without warning in worst cases
Fix: Requires engine-out service to replace IMS bearing with upgraded solution or complete engine rebuild if bearing has already failed and contaminated internals. 25-35 hours labor for preventive replacement, 60-80+ hours if full rebuild needed.
Estimated cost: $3,500-6,000 preventive, $15,000-25,000 if rebuild required
Cylinder Bore Scoring and Piston/Ring Failure
Occasional · high severityTypical onset: 80,000-140,000 mi
Symptoms: blue smoke on cold start that persists beyond warmup, excessive oil consumption (more than 1 qt per 1,000 mi), loss of compression and power, rough idle and misfires
Fix: Requires complete engine teardown with cylinder resleeve or liner installation, new pistons, rings, bearings, and machine work. Some opt for factory short block replacement. 50-70 hours labor for rebuild, less if short block swap.
Estimated cost: $12,000-20,000 rebuild, $18,000-28,000 factory short block installed
Transmission Mount and Shift Linkage Wear
Common · medium severityTypical onset: 70,000-110,000 mi
Symptoms: clunking during acceleration or deceleration, excessive driveline vibration at idle in gear, vague or notchy shifter feel, grinding into gears
Fix: Replace transmission mount (most common) and inspect shift cables/linkage bushings. Mount replacement is 2-3 hours, full linkage refresh adds another 2-3 hours.
Estimated cost: $600-1,200
Direct Ignition Coil Failure
Common · medium severityTypical onset: 60,000-100,000 mi
Symptoms: rough idle and hesitation, check engine light with misfire codes (P0300-P0306), poor fuel economy, loss of power under load
Fix: Replace failed coil(s) and spark plugs as a set. Individual coils can be diagnosed but best practice is replacing all six with plugs. 2-3 hours labor for all six cylinders on the flat-six.
Estimated cost: $800-1,400
Transmission Oil Cooler and Line Leaks
Occasional · medium severityTypical onset: 80,000-120,000 mi
Symptoms: transmission fluid spots under car, burnt smell from engine bay, low transmission fluid warnings, erratic shifting or slipping if fluid level drops significantly
Fix: Replace transmission oil cooler and hard lines as needed. Access requires partial undertray removal and can be fiddly. 3-4 hours labor depending on which lines are leaking.
Estimated cost: $800-1,500
Coolant Expansion Tank and Hose Cracking
Common · medium severityTypical onset: 70,000-110,000 mi
Symptoms: coolant smell in cabin or engine bay, visible coolant seepage around tank seams, low coolant warnings, overheating if leak becomes severe
Fix: Replace expansion tank and inspect all coolant hoses for cracks. Plastic tank develops stress cracks over time. 1.5-2.5 hours labor for tank and surrounding hoses.
Estimated cost: $400-800
Water Pump and Thermostat Failure
Occasional · high severityTypical onset: 80,000-130,000 mi
Symptoms: engine overheating, coolant leaks from pump weep hole, squealing noise from pump bearing, temperature gauge fluctuations or slow warmup with thermostat failure
Fix: Replace water pump and thermostat together as preventive measure. Requires coolant drain and refill, belt removal. 3-5 hours labor depending on access and if doing additional cooling system refresh.
Estimated cost: $1,200-2,000
Buy one if the IMS bearing has been done and bore-scope is clean, but keep a $5k repair fund for when—not if—something breaks; this generation is the sweet spot before the 718 four-cylinder but you're still gambling on engine longevity.
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.