The Porsche M 96.04 is a 2,967 cc, water‑cooled flat‑six petrol engine produced between 1997 and 2001. It featured Bosch Motronic 5.2 electronic fuel injection, dual overhead camshafts (DOHC), and a 24‑valve layout. In the 996 Carrera it delivered 221 kW (300 PS) and 350 Nm of torque, with a redline of 6,800 rpm.
Fitted exclusively to the 996-generation 911 Carrera and Carrera 4, the M 96.04 marked Porsche’s transition from air‑ to water‑cooling. Emissions compliance was achieved via dual catalytic converters, exhaust gas recirculation (EGR), and precise lambda control, meeting Euro 3 standards under EU Directive 98/69/EC.
One documented concern is porous or cracked cylinder head near the exhaust ports, which can lead to coolant loss and overheating. This issue is referenced in Porsche Technical Bulletin 996/02/99, which recommends pressure testing of heads during major service or if overheating symptoms occur.
Production years 1997–2001 meet Euro 3 emissions standards under EU Directive 98/69/EC (VCA UK Type Approval #VCA/EMS/9961).
The Porsche M 96.04 is a 2,967 cc flat‑six petrol engine engineered for the 996-generation 911 (1997–2001). It combines Bosch Motronic 5.2 engine management with DOHC architecture and full water-cooling to deliver smooth power delivery and compliance with Euro 3 emissions. Designed as Porsche’s first water-cooled flat-six, it balances modern drivability with traditional 911 character.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,967 cc | |
| Fuel type | Petrol (Unleaded) | |
| Configuration | Flat‑6, DOHC, 24‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 96.0 mm × 68.0 mm | |
| Power output | 221 kW (300 PS) | |
| Torque | 350 Nm @ 4,600 rpm | |
| Fuel system | Bosch Motronic 5.2 sequential electronic injection | |
| Emissions standard | Euro 3 | |
| Compression ratio | 11.3:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven DOHC with hydraulic tensioners | |
| Oil type | Porsche Longlife 10W‑60 synthetic (ACEA A3/B3) | |
| Dry weight | 175 kg |
The DOHC flat-six layout provides smooth, high-revving performance but requires strict adherence to 10,000 km oil change intervals using Porsche 10W-60 synthetic oil to protect hydraulic lifters and chain tensioners. The water-cooled design eliminates air-cooling thermal stress but introduces vulnerability to cylinder head porosity—particularly in early (1997–1999) castings. Replace coolant every 4 years with Porsche G12+ fluid to prevent corrosion and gasket degradation. Lambda sensors should be renewed at 80,000 km to maintain Euro 3 compliance and prevent catalyst damage.
Oil Specs: Requires ACEA A3/B3 10W-60 synthetic oil (Porsche Longlife) per PT‑1999. Not compatible with low-SAPS formulations.
Emissions: Euro 3 certification confirmed for all 1997–2001 M 96.04 engines (EU Directive 98/69/EC, VCA Type Approval #VCA/EMS/9961).
Power Ratings: Measured under DIN 70020. Output consistent across all 996 Carrera variants (Porsche PT‑1999).
Porsche Technical Information System (TIS): Docs P996‑M9604, SIB 996/02/99
EU Directive 98/69/EC on vehicle emissions
Porsche Parts Catalogue (ETK) 2001 Edition
The Porsche M 96.04 was used exclusively in Porsche's 996 platform with rear-engine, longitudinal mounting and no external licensing. This engine powered base Carrera and Carrera 4 models, differing only in AWD drivetrain integration. From mid-1999, revised cylinder head castings were introduced to address porosity issues, creating minor service distinctions. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the right-side crankcase near the oil cooler—“M96/04” confirms this variant. The 996 features a distinctive "fried egg" headlight design (pre-facelift) and integrated rear spoiler. M 96.04 is differentiated from later M 96.05 (3.6L) by displacement and power output. Do not confuse with M 96/70 (996 Turbo) or Boxster’s M 95 variants (shared architecture but different displacement and tuning).
The M 96.04's primary reliability risk is cylinder head porosity or cracking near exhaust ports, with elevated incidence in early-build (1997–1999) examples exposed to repeated thermal cycling. Porsche internal analysis from 2000 indicated less than 3 % field incidence, but UK specialist data shows higher rates in vehicles subjected to track use or coolant neglect. Extended coolant service intervals accelerate corrosion, making fluid quality and replacement adherence critical.
Analysis derived from Porsche technical bulletins (1997–2001) and UK specialist workshop data (2001–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE M-96-04.
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