The Alfa Romeo 955 A6.000 is a 2,198 cc, inline-six, naturally aspirated petrol engine produced between 1997 and 2005. It was developed as a smooth, high-revving powerplant for Alfa Romeo’s executive GT models, particularly the 166. Featuring a dual overhead camshaft (DOHC) valvetrain and sequential multi-point fuel injection (SMPI), it delivers refined performance and linear power delivery.
Fitted to models such as the 166 2.2 TS and 164 2.2, the 955 A6.000 was engineered for drivers seeking comfort, refinement, and balanced performance. Emissions compliance was achieved through a three-way catalytic converter and closed-loop lambda control, allowing it to meet Euro 3 standards across its production run.
One documented reliability concern is premature camshaft wear under sustained high-RPM operation with extended oil change intervals. This issue, referenced in Alfa Romeo Technical Service Bulletin 98B014, is linked to lubrication instability in early production units. In 1999, Alfa Romeo introduced revised camshaft profiles and hardened bearing surfaces to improve durability.
Production years 1997–2005 meet Euro 3 emissions standards (VCA UK Type Approval #VCA/EMS/5682).
The Alfa Romeo 955 A6.000 is a 2,198 cc inline-six, naturally aspirated petrol engine engineered for executive sedans (1997–2005). It combines DOHC architecture with sequential multi-point fuel injection to deliver smooth, high-RPM performance and refined driving dynamics. Designed to meet Euro 3 standards, it prioritizes balance and drivability over outright power.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,198 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-6, DOHC, 24-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 86.0 mm × 63.0 mm | |
| Power output | 110 kW (150 PS) @ 6,000 rpm | |
| Torque | 206 Nm @ 4,200 rpm | |
| Fuel system | Sequential multi-point fuel injection (SMPI) | |
| Emissions standard | Euro 3 | |
| Compression ratio | 10.3:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Timing belt (interval: 90,000 km) | |
| Oil type | SAE 10W-40, API SL/CF | |
| Dry weight | 168 kg |
The inline-six DOHC design provides smooth, high-RPM performance ideal for grand touring but requires strict adherence to 90,000 km timing belt replacement intervals to prevent catastrophic valve/piston contact. SAE 10W-40 oil meeting API SL/CF standards is essential to protect camshafts under sustained high-RPM operation. Extended idling or short-trip driving can accelerate cam lobe wear due to oil film instability. SMPI ensures crisp throttle response but demands clean fuel and regular injector servicing. Pre-1999 units should have camshafts and followers inspected per Alfa Romeo SIB 98B014; post-revision engines show improved durability. Catalytic converter longevity depends on proper air-fuel mixture control and avoidance of misfire conditions.
Oil Specs: Requires SAE 10W-40, API SL/CF specification (Alfa Romeo SIB 98B014). Compatible with ACEA A2/B2.
Emissions: Euro 3 certification applies to all 1997–2005 models (VCA Type Approval #VCA/EMS/5682).
Power Ratings: Measured under ISO 1585 standards. Output assumes premium unleaded fuel (RON 98) and clean intake system (Alfa Romeo TIS Doc. AR955A6).
Alfa Romeo Technical Information System (TIS): Docs AR955A6, SIB 98B014
VCA Type Approval Database (VCA/EMS/5682)
ISO 1585:1996 Road vehicles — Test code for fuel consumption
The Alfa Romeo 955 A6.000 was used in the Alfa Romeo 166 platform with longitudinal mounting. This engine received platform-specific adaptations—reinforced engine mounts and revised ECU mapping for improved low-end torque—and from 1999 the facelifted 166 introduced minor revisions to the intake manifold and valve cover design, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the right side of the cylinder block, near the exhaust manifold (Alfa Romeo TIS AR95590). The 8th VIN digit indicates engine type ('J' for 2.2L). Pre-1999 models have red cam covers with a single-row timing belt; post-1999 166 units use black cam covers with revised valve cover gasket design. Critical differentiation from V6 units: 955 A6.000 uses a straight-six layout with distributor-based ignition. Service parts require model-year verification—timing kits for pre-1999 164 are not interchangeable with 166 due to mounting and accessory drive differences (Alfa Romeo SIB 98B014).
The 955 A6.000's primary reliability risk is camshaft wear on pre-1999 builds, with elevated incidence in high-RPM operation. Internal Alfa Romeo quality reports from 1998 indicated a significant share of engines requiring camshaft replacement before 100,000 km, while UK DVSA records show timing belt failures as a leading cause of engine damage in neglected examples. Extended oil intervals and aggressive driving increase wear rates, making maintenance adherence critical.
Analysis derived from Alfa Romeo technical bulletins (1997-2005) and UK DVSA failure statistics (1998-2008). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about ALFA-ROMEO 955A6000.
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DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
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