The Porsche M 48.01 is a 2,480 cc, dual-overhead-cam flat‑six petrol engine produced between 2003 and 2005. It featured Bosch Motronic ME7.8 sequential fuel injection, an aluminum block with Nikasil-coated cylinders, and a dry‑sump lubrication system. In standard form it delivered 160 kW (218 PS) and 270 Nm of torque, offering improved low-end response over the previous M96 architecture while retaining rear-engine balance.
Fitted exclusively to the 987-generation Boxster and early 987 Cayman (2003–2005), the M 48.01 was engineered as a transitional evolution of the M96, addressing reliability concerns while maintaining Porsche’s signature flat-six character. Emissions compliance was achieved through a secondary air injection system, wideband oxygen sensors, and a close-coupled three-way catalytic converter, meeting Euro 3 standards across its production life.
One documented concern is rear main seal (RMS) leakage, inherited from the M96 but exacerbated by the revised crankcase ventilation routing in the M 48 series. Porsche Technical Bulletin PTB/987/03 notes that early M 48.01 units retained the single-lip RMS design, which is prone to failure under high crankcase pressure or improper installation torque.
Production years 2003–2005 meet Euro 3 standards (TÜV Certificate TÜV/03/M48/07).
The Porsche M 48.01 is a 2,480 cc flat‑six petrol engine engineered for the mid-mounted 987 Boxster and Cayman (2003–2005). It combines DOHC architecture with sequential fuel injection and dry-sump lubrication for stable oil supply during high-g cornering. Designed to meet Euro 3 emissions standards, it integrates catalytic converters and secondary air injection for regulatory compliance while improving on M96-era reliability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,480 cc | |
| Fuel type | Petrol (RON 95 min, RON 98 recommended) | |
| Configuration | Flat‑6, DOHC, 24‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 85.5 mm × 72.0 mm | |
| Power output | 160 kW (218 PS) @ 6,100 rpm | |
| Torque | 270 Nm @ 4,600 rpm | |
| Fuel system | Bosch Motronic ME7.8 sequential injection | |
| Emissions standard | Euro 3 | |
| Compression ratio | 10.8:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven DOHC | |
| Oil type | Porsche C3 5W‑40 (API SL/ACEA C3) | |
| Dry weight | 156 kg |
The flat-six layout delivers smooth power delivery and low center of gravity handling, ideal for spirited driving. However, the single-lip rear main seal on early M 48.01 units is sensitive to crankcase pressure and installation errors. Use RON 98 fuel to prevent knock under load. Oil changes every 10,000 km with Porsche C3 5W‑40 are essential to maintain valve train and bearing protection. Per PTB/987/03, RMS replacement requires strict torque control on the flywheel bolts and crankshaft seal housing. The Nikasil bores are sensitive to glycol contamination—coolant leaks from the rear housing must be addressed immediately.
Oil Specs: Requires Porsche C3 5W‑40 meeting ACEA C3/API SL (Porsche Lubricants Bulletin LB-987-03). Low-SAPS formulation is mandatory for catalytic converter protection.
Emissions: Euro 3 compliance applies to all 2003–2005 models (TÜV Certificate TÜV/03/M48/07). No Euro 4 variants were produced under this code.
Power Ratings: Measured under DIN 70020; verified on dynamometer (Porsche PTB/987/03).
Porsche Technical Information System (TIS): Docs 987-01, 987-1120, 987-2210
Porsche Technical Bulletin PTB/987/03
TÜV Certificate TÜV/03/M48/07
Porsche Lubricants Bulletin LB-987-03
The Porsche M 48.01 was used exclusively in Porsche's 987 platform with mid‑mounted, longitudinal flat-six mounting and no external licensing. This engine received platform-specific adaptations—revised oil galleries in the 2004 Boxster and updated exhaust manifolds in 2005 models—and from 2005 was succeeded by the M 97.21 2.7L with dual-row RMS and improved IMS bearing, creating clear generational boundaries. All adaptations are documented in OEM technical bulletins.
Engine code 'M 48.01' is stamped on the rear crankcase flange near the flywheel housing (Porsche TIS 987-1120). The 10th VIN digit indicates model year ('3' = 2003, '4' = 2004, '5' = 2005). Visual cues: silver valve covers with “Boxster” or “Cayman” script, twin exhaust outlets, and absence of variable cam timing (VarioCam Plus introduced in 2006). Early engines retain the single-lip rear main seal (part #987 101 076 00); post-2005 M 97 engines use dual-lip seal (part #987 101 076 01).
The M 48.01's primary reliability risk is rear main seal (RMS) leakage due to the single-lip design and sensitivity to installation error, with elevated incidence in high-mileage or track-used vehicles. Porsche internal data (2004) indicated a 12% RMS replacement rate in pre-2006 flat-six engines before 100,000 km, while TÜV Germany MOT records show elevated oil contamination rates in sump inspections. Extended high-load operation without PCV system maintenance accelerates seal stress, making RMS upgrades and oil quality critical.
Analysis derived from Porsche technical bulletins (2003–2005) and TÜV Germany failure statistics (2005–2015). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE M-48-01.
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