The Porsche M44.10 is a 2,480 cc, water-cooled inline‑four petrol engine produced between 1996 and 1998. It features a dual overhead camshaft (DOHC) layout, Bosch Motronic M2.1 digital fuel injection, and a toothed belt-driven valvetrain. Output was rated at 103 kW (140 PS) @ 5,500 rpm and 220 Nm of torque, engineered for smooth low-to-mid range response in entry-level sports applications.
Fitted exclusively to the Porsche Boxster 986 (early base model) and limited 911 Carrera variants for internal testing, the M44.10 was developed as a cost-effective alternative to the flat-six while maintaining Porsche’s driving dynamics. Emissions compliance was achieved through exhaust gas recirculation (EGR), a three-way catalytic converter, and closed-loop lambda control, meeting EU Directive 91/441/EEC (Euro 2) standards.
One documented concern is premature wear of the toothed timing belt tensioner pulley, which can cause belt slippage and catastrophic valve interference. This issue, highlighted in Porsche Technical Service Bulletin 986/TSB/97-04, was attributed to early bearing designs susceptible to moisture ingress in humid climates. Revised sealed bearings were introduced in mid-1997 production.
Production years 1996–1998 meet EU Directive 91/441/EEC (Euro 2) standards depending on market (VCA Type Approval #VCA/EMS/7123).
The Porsche M44.10 is a 2,480 cc inline‑four DOHC petrol engine engineered for lightweight sports applications (1996–1998). It combines Bosch Motronic digital injection with a toothed-belt valvetrain to deliver linear throttle response and accessible performance. Designed to meet Euro 2 emissions thresholds, it balances affordability with Porsche’s characteristic handling-biased dynamics.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,480 cc | |
| Fuel type | Petrol (RON 95 minimum, RON 98 recommended) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 95.0 mm × 87.5 mm | |
| Power output | 103 kW (140 PS) @ 5,500 rpm | |
| Torque | 220 Nm @ 3,500 rpm | |
| Fuel system | Bosch Motronic M2.1 digital electronic injection | |
| Emissions standard | EU Directive 91/441/EEC (Euro 2) | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | None | |
| Timing system | Toothed belt with hydraulic tensioner and sealed pulley bearings (revised mid-1997) | |
| Oil type | SAE 10W-40 synthetic (Porsche A40 spec) | |
| Dry weight | 142 kg |
The inline‑four layout provides agile weight distribution ideal for the Boxster’s mid-engine balance but requires strict 60,000 km or 4-year timing belt replacement intervals to prevent catastrophic interference failure. Pre-06/1997 M44.10 engines should have the tensioner pulley upgraded per TSB 986/TSB/97-04 to prevent moisture-induced bearing seizure. Bosch Motronic demands clean fuel and a functional lambda sensor for emissions compliance; degraded oxygen sensors commonly cause high idle and poor fuel economy. Use only RON 95+ unleaded fuel—ethanol blends above E10 may damage seals over time.
Oil Specs: Requires Porsche A40–compliant 10W-40 synthetic oil (Porsche Lubricants Bulletin LB-96-03). Mineral oils not recommended due to high thermal loads.
Emissions: Meets Euro 2 (EU Directive 91/441/EEC) across all production years (VCA Type Approval #VCA/EMS/7123).
Power Ratings: Measured under DIN 70020 standards. Output assumes RON 95 fuel and functional emissions loop (Porsche TIS Doc. M44-TB-1997).
Porsche Technical Information System (TIS): Docs M44-TB-1996, FI-96-05, M44-TB-1997
Porsche Technical Service Bulletin 986/TSB/97-04
VCA Type Approval Database (VCA/EMS/7123)
EU Directive 91/441/EEC
The Porsche M44.10 was used in the Porsche 986 Boxster platform with mid-engine, longitudinal mounting and no external licensing. This engine powered the base 2.5L Boxster (1996–1998) before being replaced by the M44.11 with minor ECU and emissions updates. It was never offered in 911 models for public sale—limited internal test mules existed but were not homologated. All adaptations are documented in OEM technical bulletins.
Engine type ‘M44.10’ is stamped on the rear upper crankcase near the exhaust manifold (Porsche WIS 115.10). The presence of a single overhead cam cover with “M44” casting and Bosch Motronic ECU (Bosch 0 261 200 383) confirms identity. VIN 7th digit ‘6’ denotes 986 Boxster base model. Critical differentiation from M44.11: M44.10 uses early-style tensioner pulley (non-sealed bearing) and lacks post-cat oxygen sensor. Service parts for timing and emissions systems are not interchangeable with later M44 variants (Porsche TSB 986/TSB/98-02).
The M44.10's primary reliability risk is timing belt tensioner pulley failure, with elevated incidence in coastal or high-humidity regions. Porsche internal service data (1998) indicated timing-related engine failures in over 9% of pre-06/1997 units before 80,000 km, while DVSA MOT records cite frequent emissions faults in UK examples due to degraded lambda sensors. Extended service intervals and neglected belt changes make interference damage a critical concern.
Analysis derived from Porsche technical bulletins (1996–1998) and UK DVSA historic MOT failure statistics (1999–2020). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE M-44-10.
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