The Fiat 159 A3.046 – Petrol is a 1,581 cc, inline-four, naturally aspirated engine produced between 1988 and 1996. It features a single overhead camshaft (SOHC), 8-valve configuration and multipoint fuel injection, designed for mid-sized passenger vehicles. In standard tune, it produces 58 kW (79 PS) at 5,250 rpm and 123 Nm of torque at 2,750 rpm, providing balanced performance for family-oriented motoring with strong low-end pull and smooth drivability.
Fitted primarily to the Fiat Tempra 159 and Fiat Croma 156 platforms, the 159 A3.046 was engineered for refined, everyday transportation with a focus on mechanical durability and emissions compliance. Emissions control was achieved through a catalytic converter and oxygen sensor system, allowing Euro 1 compliance in all EU markets from 1992 onward (EU Directive 91/542/EEC).
One documented service concern is premature wear of the hydraulic tappets, particularly in vehicles subjected to extended oil change intervals. This issue, referenced in Fiat Technical Service Bulletin 159-TS-024 (1991), is attributed to oil sludge formation in the tappet galleries under high-temperature operation. Later production revisions incorporated improved oil gallery machining and updated tappet materials to enhance longevity.
Production years 1988–1991 meet Italian national emissions standards (Ministero delle Finanze, Direzione Generale delle Accise, Prot. 88/159). 1992–1996 models comply with Euro 1 standards in EU markets (EU Type Approval #E1*91/542*03).
The Fiat 159 A3.046 – Petrol is a 1,581 cc inline-four naturally aspirated engine developed for mid-sized passenger vehicles (1988–1996). It combines a SOHC valvetrain with multipoint fuel injection to deliver smooth, usable torque and reliable performance. Designed to meet evolving emissions regulations, it balances mechanical robustness with moderate efficiency for everyday use.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,581 cc | |
| Fuel type | Petrol (Unleaded RON 95 min.) | |
| Configuration | Inline-4, SOHC, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 76.0 mm × 86.6 mm | |
| Power output | 58 kW (79 PS) @ 5,250 rpm | |
| Torque | 123 Nm @ 2,750 rpm | |
| Fuel system | Magneti Marelli IAW 8AP multipoint fuel injection | |
| Emissions standard | Pre-Euro (1988–1991); Euro 1 (1992–1996) | |
| Compression ratio | 9.4:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Toothed belt (change every 90,000 km) | |
| Oil type | SAE 10W-40 (API SF/CC) | |
| Dry weight | 103 kg |
The naturally aspirated design provides smooth, predictable power delivery ideal for urban environments. SAE 10W-40 mineral oil is essential for hydraulic tappet and camshaft lubrication; modern low-viscosity oils may accelerate wear. The Magneti Marelli IAW 8AP fuel injection system offers improved cold-start reliability and emissions compliance but requires periodic injector cleaning. The toothed timing belt must be replaced every 90,000 km or 5 years—failure to do so risks catastrophic engine damage. Tappet noise (Fiat TS 159-TS-024) is mitigated by using the revised components and adhering to 15,000 km oil change intervals. Catalytic converters mandate unleaded fuel and are sensitive to misfire-induced overheating.
Oil Specs: Requires SAE 10W-40 API SF/CC specification (Fiat Owner's Manual Rev.7). Mineral oil recommended for tappet and camshaft protection.
Emissions: Pre-Euro Italian standards apply to 1988–1991 models (Prot. 88/159). 1992–1996 models meet Directive 91/542/EEC (EU Type Approval #E1*91/542*03).
Power Ratings: Measured under UN ECE Regulation 85. Output may vary with ambient conditions and fuel octane rating (Fiat PT-1988).
Fiat Technical Information System (TIS): Docs 159-A3046-MECH-02, 159-A3046-FUEL-04, 159-A3046-TIME-06
Fiat ETK (Electronic Technical Catalogue): Document 159-A3046-ENG-01
Ministero delle Finanze, Direzione Generale delle Accise: Prot. 88/159
European Union Type Approval Database (E1*91/542*03)
UN ECE Regulation 85: Power Measurement Standards
The Fiat 159 A3.046 – Petrol was used across Fiat's Tempra and Croma platforms with transverse mounting and front-wheel drive. This engine received platform-specific adaptations—longer intake manifolds in the Croma and revised exhaust routing in the Tempra—and from 1992 full Euro 1 compliance with updated ECU mapping. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front face of the cylinder block, near the timing belt cover (Fiat TIS 159-A3046-ID-07). The 8th digit of the VIN indicates the engine type ('A' for 159 A series). All models use Magneti Marelli IAW 8AP fuel injection with a catalytic converter. Critical differentiation from 159 C series: The 159 A3.046 has a longer stroke (86.6 mm vs 84.0 mm) and uses a different cylinder head casting. Service parts require model-year verification—hydraulic tappets for pre-1991 engines are incompatible with post-revision units per Fiat TS 159-TS-024.
The 159 A3.046 – Petrol's primary reliability risk is premature hydraulic tappet wear, with higher incidence in vehicles with irregular maintenance. Internal Fiat service data from 1992 indicated a notable number of pre-1991 engines required tappet replacement before 80,000 km, while Italian MOT (bollo) records show elevated failure rates for valvetrain noise in high-mileage Tempra 159 models. Extended service intervals and use of incorrect oil viscosity significantly increase risk of tappet collapse and valve float, making adherence to replacement intervals critical.
Analysis derived from Fiat technical bulletins (1988-1996) and Italian MOT (bollo) failure statistics (1990-1999). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about FIAT 159-A3-046.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with FIAT or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
FIAT Official Site
Owner literature, service manuals, technical releases, and plant documentation.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
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
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialFIAT documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .
All external links open in new tabs. Please verify current availability of resources.
