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 (VCA UK Type Approval #VCA/EMS/9501). 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 | Porsche-approved 0W-40 or 5W-40 (ACEA A3/B4) | |
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.
The M 97.74's primary reliability risk is IMS bearing wear in early (2005–2006) production, with elevated incidence in track-driven or cold-start aggressive use. Porsche internal service data from 2007 noted IMS-related concerns in ~6% of pre-2007 Boxster S engines before 100,000 km under performance conditions, while UK DVSA records show strong baseline reliability in standard road applications. Extended high-RPM operation without warm-up increases thermal stress, making operating discipline critical.
Analysis derived from Porsche technical bulletins (2005-2008) and UK DVSA failure statistics (2010-2023). 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.
Yes. Common upgrades include ECU remap (+20–30 PS), sports exhaust, and air filter. Forced induction is rare. Stock internals safely handle up to ~320 PS with supporting modifications. Most owners prioritize IMS reliability before tuning.
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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