The Porsche M 97.74 is a 3,387 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 electronic fuel injection. In standard Boxster S (987) form it delivered 206 kW (280 PS) and 330 Nm of torque, with responsive mid — range thrust and high — revving character ideal for agile roadster dynamics.
Fitted exclusively to the Porsche Boxster S (987) from 2005 to 2008—the first generat…
Production years 2005–2008 meet Euro 4 standards . No Euro 5 variants were produced for this engine family.
The Porsche M 97.74 is a 3,387 cc water-cooled flat‑six petrol engine engineered for the Boxster S (987) (2005–2008). It combines DOHC architecture with Bosch Motronic ME7.8 electronic fuel injection to deliver smooth, high-revving performance. Designed to meet Euro 4 emissions standards, it integrates twin catalytic converters, EGR, and secondary air injection for full regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,387 cc | |
Fuel type | Petrol (RON 98 min) | |
Configuration | Flat-6, DOHC, 24-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 96.0 mm × 78.5 mm | |
Power output | 206 kW (280 PS) @ 6,700 rpm | |
Torque | 330 Nm @ 4,750 rpm | |
Fuel system | Bosch Motronic ME7.8 electronic injection | |
Emissions standard | Euro 4 | |
Compression ratio | 11.3:1 | |
Cooling system | Water-cooled (dual-circuit) | |
Turbocharger | None | |
Timing system | Chain-driven DOHC (maintenance-free design) | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 156 kg |
The Porsche M 97.74 was used exclusively in Porsche's Boxster S (987) platform with mid-engine, longitudinal mounting and no external licensing. This engine featured updated oil pump and crankcase ventilation over the M 96—and from 2009 the facelifted 987.2 adopted the direct-injection M97/75, creating a hard interchange limit. All adaptations are documented in OEM technical bulletins.
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Field reports and technical service bulletins highlight component wear patterns under high-load operation. Adherence to manufacturer service intervals and approved fluid specifications is critical for long-term reliability.
Analysis derived from manufacturer technical service bulletins and industry workshop records. Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The M 97.74 is generally reliable for road use, with significant IMS improvements over the M 96. However, 2005–2006 engines still carry measurable IMS risk. With quality oil, RON 98 fuel, and proactive IMS inspection, many examples exceed 200,000 km without major issues. Post-2006 units benefit from bearing revisions.
Top concerns include IMS bearing wear (early engines), rear main seal leaks, Motronic sensor drift (O2/MAF), and VarioCam solenoid failure. IMS issues are the most critical due to potential engine seizure. All are documented in Porsche service bulletins.
Exclusively the Porsche Boxster S (987) from 2005 to 2008 (3.4L). It was the performance engine for the first-generation 987 roadster. No other manufacturer used this engine; it was replaced by the direct-injection M97/75 in the 987.2 facelift from 2009.
Aftermarket ECU tuning is common on the M-97-74 platform, but increasing boost or altering engine parameters accelerates component wear, impacts emissions compliance, and may void vehicle warranties. Any modifications should be evaluated carefully by a qualified specialist.
Moderate consumption. Expect 11–13 L/100km (26–22 mpg UK) in mixed driving. Highway cruising at 120 km/h yields ~9.2 L/100km. Aggressive driving exceeds 15 L/100km. Figures reflect mid-2000s naturally aspirated flat-six norms.
Yes. The M 97.74 is an interference design. If the timing chain fails (extremely rare), valve-to-piston contact will occur, causing severe internal damage. However, chain failure is uncommon due to robust design.
Porsche recommends 0W-40 or 5W-40 synthetic oil meeting ACEA A3/B4 (e.g., Mobil 1 ESP 0W-40 or Porsche-approved equivalent). Change every 10,000 km or annually. Low-SAPS oils must be avoided.
Comprehensive technical documentation and regulatory references
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Official guidance on engine swaps and inspection implications.
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
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