The 2007 Boxster (987.1 generation) with the 2.7L M96 engine is a sweet-handling roadster plagued by the infamous intermediate shaft bearing failure and bore scoring issues that can grenade an otherwise solid motor. These aren't minor repairs—they're engine-out, wallet-emptying events.
Intermediate Shaft (IMS) Bearing Failure
Occasional · high severityTypical onset: 40,000-80,000 mi
Symptoms: Metallic debris in oil during changes, Sudden loss of oil pressure, Catastrophic engine failure with metal-on-metal grinding, Often no warning until it grenades
Fix: Preventive replacement requires engine/transmission separation, rear main seal area access, IMS bearing upgrade to single-row or ceramic hybrid. If it fails, you're rebuilding or replacing the entire engine. Figure 16-24 labor hours for preventive service, 40-60+ hours for full engine rebuild after failure.
Estimated cost: $2,500-4,000 preventive, $15,000-25,000 if it fails and requires rebuild
Cylinder Bore Scoring (Lokasil Cylinder Wear)
Occasional · high severityTypical onset: 60,000-100,000 mi
Symptoms: Excessive oil consumption (quart every 500-1,000 miles), Blue smoke on startup or hard acceleration, Low compression on one or more cylinders, Rough idle and misfires as it progresses
Fix: Nikasil/Lokasil coated cylinders wear prematurely, especially on early M96/M97 engines. Only real fix is complete engine rebuild with LN Engineering or similar aftermarket sleeves, or used/rebuilt engine replacement. Engine-out job, 50-70 labor hours minimum.
Estimated cost: $18,000-28,000 for complete rebuild with sleeves, $12,000-18,000 for used engine swap
Rear Main Seal (RMS) Oil Leak
Common · medium severityTypical onset: 50,000-90,000 mi
Symptoms: Oil puddles under rear of engine/transmission bell housing, Oil dripping onto exhaust causing burning smell, Visible oil seepage at engine-transmission junction, Often misdiagnosed as IMS bearing leak
Fix: Requires engine/transmission separation to access the rear main seal. Often done simultaneously with IMS bearing service since you're already in there. 14-18 labor hours as standalone job, add 4-6 hours if combining with IMS.
Estimated cost: $2,200-3,500 standalone, $3,500-5,500 combined with IMS service
Coolant Expansion Tank Cracking
Common · medium severityTypical onset: 70,000-120,000 mi
Symptoms: Coolant smell in engine bay, Visible cracks in plastic tank, often at seams, Low coolant warning light, Coolant drips on ground, usually passenger side
Fix: Plastic tank becomes brittle with heat cycles and develops stress cracks. Simple replacement, tank is accessible in rear compartment. 1.5-2.5 labor hours including proper bleeding of cooling system.
Estimated cost: $400-700
Water Pump Failure
Occasional · medium severityTypical onset: 80,000-120,000 mi
Symptoms: Squealing or grinding noise from rear of engine, Coolant leak from pump housing, Overheating or erratic temperature gauge, Visible coolant puddle under car after sitting
Fix: Water pump is engine-driven and buried. Requires significant disassembly of rear engine area, belts, and accessories. Often done with other cooling system maintenance. 6-9 labor hours.
Estimated cost: $1,500-2,500
Convertible Top Hydraulic System Leaks
Common · low severityTypical onset: 60,000-100,000 mi
Symptoms: Top moves slowly or stops mid-cycle, Hydraulic fluid puddles in front trunk, Top won't latch or unlatch properly, Visible fluid on hydraulic rams or lines
Fix: Hydraulic rams, lines, and pump seals deteriorate. Individual ram replacement is 3-5 hours each side, lines are 2-3 hours, pump rebuild is 4-6 hours. Often multiple components leak simultaneously.
Estimated cost: $800-1,500 per ram, $1,200-2,000 for pump, $300-600 for lines
Air Oil Separator (AOS) Failure
Occasional · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Excessive smoking from exhaust on deceleration, Oil in intake system or throttle body, Rough idle when warm, Check engine light for lean/rich codes from oil ingestion
Fix: The AOS separates oil from crankcase vapors; when diaphragm fails, oil gets sucked into intake. Located under intake manifold on passenger side. 4-6 labor hours for replacement.
Estimated cost: $1,000-1,800
Buy only if IMS bearing has been done or you budget $3-4k immediately for preventive service; otherwise it's a $20k engine failure waiting to happen, but the driving experience is exceptional if you can stomach the risk.
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.