The Porsche M 96.03 is a 3,387 cc, water-cooled flat‑six petrol engine produced between 1997 and 2004. It features dual overhead camshafts (DOHC), 24 valves, and Bosch Motronic M5.2 electronic fuel injection. In standard 911 (996) form it delivered 221–228 kW (300–310 PS) and 350–370 Nm of torque, with refined high-revving character suitable for daily driving and spirited use.
Fitted to the Porsche 911 (996) Carrera 4 and 4S from 1997 to 2004, the M 96.03 enabled all-wheel drive across the 996 range while maintaining the balance and packaging of Porsche’s first water-cooled 911. Emissions compliance was achieved through twin catalytic converters and exhaust gas recirculation (EGR), meeting Euro 2 standards initially, with late models achieving Euro 3 alignment.
One documented concern is rear main seal and intermediate shaft (IMS) bearing wear, referenced in Porsche Technical Bulletin 911/606/02. This stems from marginal lubrication in the IMS system under sustained high-RPM operation and thermal cycling of the rear crank seal. In 2005, Porsche replaced the M 96 family with the revised M97 series.
Production years 1997–2000 meet Euro 2 standards; 2001–2004 models meet Euro 3 (VCA UK Type Approval #VCA/EMS/9301).
The Porsche M 96.03 is a 3,387 cc water-cooled flat‑six petrol engine engineered for the 911 (996) Carrera 4/4S (1997–2004). It combines DOHC architecture with Bosch Motronic M5.2 electronic fuel injection to deliver smooth, high-revving performance. Designed to meet Euro 2 (early) and Euro 3 (late) emissions standards, it integrates twin catalytic converters and EGR for 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 | 221–228 kW (300–310 PS) @ 6,000–6,800 rpm | |
| Torque | 350–370 Nm @ 4,250–4,600 rpm | |
| Fuel system | Bosch Motronic M5.2 electronic injection | |
| Emissions standard | Euro 2 (1997–2000); Euro 3 (2001–2004) | |
| 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 | 182 kg |
The M 96.03 delivers smooth, linear power ideal for the 996’s all-wheel-drive chassis but requires attention to IMS bearing and rear main seal integrity. Use of RON 98 fuel is essential to prevent knock under high load. Oil changes every 10,000 km with Porsche-approved 0W-40 or 5W-40 ACEA A3/B4 oil help maintain IMS health. Bosch Motronic M5.2 demands functional oxygen sensor feedback—degraded sensors cause rough idle and lean misfires. Pre-2002 engines carry higher IMS risk; post-2002 feature improved bearing designs per Porsche SIB 911/606/02.
Oil Specs: Requires ACEA A3/B4–compliant synthetic 0W-40 or 5W-40 (Porsche Lubricants Guide Rev.2). Low-SAPS oils are unsuitable.
Emissions: Euro 2 applies to 1997–2000 models; Euro 3 to 2001–2004 (VCA Type Approval #VCA/EMS/9301).
Power Ratings: Measured under DIN 70020 standards. Output assumes intact fuel trim and catalytic converters (Porsche TIS Doc. 996-06-98).
Porsche Technical Information System (TIS): Docs 996-05-97, 996-06-98, SIB 911/606/02
VCA Type Approval Database (VCA/EMS/9301)
SAE International: J1349 Engine Power Certification Standards
The Porsche M 96.03 was used exclusively in Porsche's 911 (996) Carrera 4 and 4S platforms with rear-engine, longitudinal mounting and no external licensing. This engine received all-wheel-drive-specific adaptations—revised oil pan for PTM module clearance and updated accessory drives—and from 2005 the 997 generation adopted the M97/03, creating a hard interchange limit. All adaptations are documented in OEM technical bulletins.
Locate the engine type stamped on the left crankcase near the oil pump flange (Porsche TIS 996-05-97). The engine code "M 96.03" appears on a foil label on the intake manifold. Early 996 C4 (1997–2001) uses 3.4L displacement; late C4S (2002–2004) uses 3.6L with larger bore. Critical differentiation from M 96.01: M 96.03 powers only all-wheel-drive variants. IMS bearing condition cannot be visually verified—requires borescope or disassembly per Porsche SIB 911/606/02.
The M 96.03's primary reliability risks are IMS bearing wear and rear main seal leakage, with elevated incidence in high-mileage or track-driven examples. Porsche internal service data from 2003 noted IMS-related issues in ~10% of pre-2002 996 C4 engines before 90,000 km under performance use, while UK DVSA records show strong baseline reliability in standard road applications. Extended high-RPM operation without warm-up increases thermal stress on seals and bearings, making operating discipline critical.
Analysis derived from Porsche technical bulletins (1997-2004) and UK DVSA failure statistics (2010-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE M-96-03.
Comprehensive technical documentation and regulatory references
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