Porsche Boxster 2.7 987

The M96.25 engine in the 987.1 uses the Gen III IMS bearing, a larger dual-row design with an estimated failure rate of approximately 1%. This is a significant improvement over the 986's single-row bearing (8-10% failure rate). Early 2005 production cars may still have the older Gen II bearing with higher failure rates, so verify the build date. When the bearing does fail, metal debris circulates through the oil system and causes catastrophic internal damage requiring a full engine rebuild (€8,000-12,000). Preventive IMS bearing upgrade costs €1,500-2,500 including labor (8-10 hours, gearbox must be removed). Most specialists recommend combining the IMS upgrade with rear main seal and clutch replacement since the gearbox is already out, bringing the total combined job to €3,000-5,000. If the car already has documented IMS upgrade with a reputable kit (LN Engineering, Flat 6 Innovations), this risk drops to near zero.

The rear main seal sits where the crankshaft exits the engine to meet the gearbox. Porsche redesigned this seal multiple times across the 987 production run, but the issue persists, particularly on cars above 80,000-100,000 km. When the seal fails, oil contaminates the flywheel and clutch disc. In severe cases the contaminated clutch requires replacement as well. The seal itself costs under €50, but the gearbox must be removed for access (8-10 hours labor). Standalone RMS replacement costs €1,200-1,800 at a specialist. Most workshops recommend combining RMS with clutch renewal and IMS bearing upgrade (on 987.1) since the gearbox is already removed. Always use the latest PTFE seal revision (part number 0PB-105-249). Porsche Zentrum labor rates push the standalone job to €2,000-2,500.

The AOS is a crankcase ventilation device that separates oil from blow-by gases. The internal diaphragm deteriorates with age and heat exposure, typically failing between 60,000-100,000 km. Symptoms include hunting idle, increased oil consumption, blue or white exhaust smoke on cold start, and various fault codes. The genuine Porsche replacement part costs €80-150 and is a known maintenance item. Labor runs 3-4 hours on the Boxster due to access constraints. Total replacement at a specialist is €400-900. If left uncorrected, a failed AOS can contribute to bore scoring by leaning out the fuel mixture and allowing oil to foul intake components. Aftermarket AOS units have mixed longevity; specialists recommend using genuine Porsche parts. Some owners treat this as scheduled maintenance, replacing it every 6 years or 100,000 km regardless of symptoms.

Two related cooling system weak points affect the 987.1. The water pump uses a plastic impeller that can shed blades over time, reducing coolant flow and causing localized overheating. Broken impeller fragments can block passages in the cylinder heads. Separately, the plastic coolant collection unit between the engine and cabin bulkhead becomes brittle after years of heating and cooling, developing cracks that leak under pressure. Accessing this part requires lowering the engine 50-75 mm, making it labor-intensive. Water pump replacement costs €400-700 (upgraded metal impeller pumps are available). Coolant pipe assembly replacement costs €600-900 due to labor access. Both should be considered preventive maintenance on any car still running original components. Watch for slow coolant level drops or faint coolant smell while driving. Overheating from cooling system failure accelerates bore scoring risk.

The electrically operated convertible top uses transmission gearboxes with internal plastic gears, push rods, cables, and motors. The most common failure is cracked plastic gears inside the transmission units, which cause clunking noises during operation and eventually prevent the roof from opening or closing completely. Replacement gears cost €80-100 in parts with 3-4 hours labor, making it affordable if caught early. Push rod failures are similarly inexpensive. However, if the electric motor or complete transmission assembly needs replacement, costs rise to €1,500-2,500. Porsche dealers quote €2,500+ for motor and transmission replacement, but the actual fix is often just a replacement gear. The convertible top fabric itself lasts approximately 10-15 years before showing wear. Regular use and lubrication of guide rails extends mechanism life. Cars that sit unused for long periods tend to develop more roof mechanism problems.

The M96 engine's open-deck crankcase allows cylinders to distort under thermal stress. Cylinder 6 runs hottest and is most susceptible. However, the 2.7L base engine is considerably less prone to bore scoring than the 3.2L S variant. The smaller displacement puts less thermal stress on the cylinders. Forum evidence and specialist experience suggests bore scoring on 2.7L engines is rare. A bore scope inspection before purchase costs €100-200 and is essential for any 987.1. If scoring is found, repair requires Nickies cylinder sleeves with forged pistons, costing €5,000-6,000 for cylinder work plus €4,000-6,000 for engine removal and rebuild. Prevention includes frequent oil changes (every 10,000 km maximum), using quality synthetic oil, replacing the AOS before it fails, and ensuring the cooling system is in good condition.

Manual-equipped 987.1 Boxsters use shift cables with rubber bushings that deteriorate over time, creating increased play in the shift lever. The bushings wear gradually, with most cars developing noticeable sloppiness between 70,000-120,000 km. The original pivot lever uses multiple pieces with rubber bushings that are prone to degradation. Individual bushing kits are available from companies like Numeric Racing, which replaces the worn rubber inserts with Delrin and aluminum for around €150-200. If the cables themselves have failed (common between 70,000-120,000 km), complete cable replacement is needed. Upgraded cables with an 981-design one-piece pivot lever are available and provide a permanent improvement. Total repair with upgraded parts and labor runs €500-800 at a specialist. This is a comfort and driving experience issue rather than a safety concern.

The 987 Boxster's front-mounted radiators and AC condensers sit behind open vents with no protective screens from the factory. Leaves, road debris, and insects accumulate between the radiator and condenser, trapping moisture that causes progressive corrosion. Once corrosion starts, the aluminum cores develop pinhole leaks that cannot be reliably repaired. Radiator replacement costs €400-800 per unit (there are two), and AC condenser replacement costs €300-600. Both condensers should be replaced at the same time, along with the receiver/drier. Total cost for replacing both radiators and condensers can reach €1,200-2,000. Prevention is straightforward: clean out debris from behind the front bumper every spring and consider installing aftermarket mesh screens. Reduced cooling efficiency manifests as slightly higher running temperatures, especially in traffic.