The Porsche M 55.02 is a 3,192 cc, water‑cooled flat‑six petrol engine produced between 2005 and 2008. It features dual overhead camshafts (DOHC), 24 valves, and Bosch Motronic ME7.8 sequential fuel injection with VarioCam Plus variable valve timing. In standard form it delivered 188 kW (255 PS) at 6,200 rpm, with peak torque of 310 Nm at 4,800 rpm.
Fitted to the Porsche Boxster S (987) and Cayman S (987) models globally, the M 55.02 offered enhanced performance over the base flat‑six through higher displacement, revised intake geometry, and variable valve timing. Emissions compliance was achieved through three‑way catalytic converters and precise lambda control, enabling full Euro 4 compliance across all production regions.
One documented concern is premature wear of the VarioCam actuator solenoid and cam phaser mechanism, highlighted in Porsche Service Bulletin 987 08 2006. This issue stems from oil contamination and thermal cycling, potentially causing rough idle, reduced low‑end torque, and cam timing fault codes.
Production years 2005–2008 meet Euro 4 emissions standards (VCA UK Type Approval #VCA/EMS/9456).
The Porsche M 55.02 is a 3,192 cc flat‑six DOHC petrol engine engineered for performance-oriented mid-engine sports applications (2005–2008). It combines water cooling with VarioCam Plus variable valve timing and sequential fuel injection to deliver strong mid‑range response and high‑revving character. Designed to meet Euro 4 emissions standards, it balances track-capable output with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,192 cc | |
| Fuel type | Petrol (RON 98 min) | |
| Configuration | Flat‑6, DOHC, 24‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 89.0 mm × 85.0 mm | |
| Power output | 188 kW (255 PS) @ 6,200 rpm | |
| Torque | 310 Nm @ 4,800 rpm | |
| Fuel system | Bosch Motronic ME7.8 sequential injection with VarioCam Plus | |
| Emissions standard | Euro 4 | |
| Compression ratio | 11.3:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven DOHC with VarioCam Plus hydraulic phasers | |
| Oil type | Porsche A40 (SAE 5W-40) | |
| Dry weight | 180 kg |
The VarioCam Plus system enables strong low-end torque and high-RPM power but demands clean, high-quality oil to prevent solenoid and phaser clogging. Porsche A40 (5W-40) oil is essential for cam and bearing protection under sustained high-load use. Cold starts should be followed by gentle warm-up to ensure oil circulation through the VarioCam actuators. Extended oil change intervals or contaminated oil accelerate phaser wear, leading to timing faults. Regular oil changes and use of OEM oil filter are critical.
Oil Specs: Requires Porsche A40 (5W-40) specification (Porsche SIB 987 09 2007). ACEA A3/B4 equivalent acceptable if A40 unavailable.
Emissions: Euro 4 certification applies to all 2005–2008 models (VCA Type Approval #VCA/EMS/9456).
Power Ratings: Measured under DIN 70020 standards. Peak output requires RON 98 fuel and functional catalyst (Porsche TIS Doc. 987-6512).
Porsche Technical Information System (TIS): Docs 987-6501, 987-6512, SIB 987 08 2006
VCA Type Approval Database (VCA/EMS/9456)
SAE International: J1349 Engine Power Certification Standards
The Porsche M 55.02 was used across Porsche's 987 Boxster S and 987 Cayman S platforms with mid-engine, longitudinal mounting and no external licensing. This engine received minor running changes—revised VarioCam solenoid seals in 2007–2008 and updated ECU maps—and was replaced in 2009 by the direct-injection M97/22. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the rear crankcase near the flywheel housing (Porsche TIS 987-6600). The engine number begins with "M55/". The M 55.02 is identified by its 3.2L displacement, VarioCam Plus solenoids on each cam cover, and dual oil filler caps. Visual cue: 2005–2008 Boxster S/Cayman S models feature red brake calipers and 18-inch wheels. Do not confuse with base M48.02—VarioCam Plus solenoids and larger displacement are key differentiators.
The M 55.02's primary reliability risk is VarioCam actuator solenoid failure, with elevated incidence in high-mileage or infrequently serviced examples. Porsche internal service data from 2007 indicated over 12% of 2005–2006 engines required VarioCam repairs before 100,000 km, while owner surveys link cam timing faults to oil contamination. Extended oil change intervals and use of non-spec oil accelerate wear, making OEM-spec oil and solenoid inspection critical.
Analysis derived from Porsche technical bulletins (2005–2008) and owner association failure logs (2009–2020). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE M-55-02.
Comprehensive technical documentation and regulatory references
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