The Fiat 159 A4.000 is a 1,586 cc, inline — four, naturally aspirated petrol engine produced between 1987 and 1995. It features a single overhead camshaft (SOHC), 8 — valve configuration, and electronic fuel injection via a Magneti Marelli IAW 1AV system. In standard tune, it delivers 57 kW (78 PS), offering improved drivability and emissions control over earlier carburetted variants.
Fitted primarily to the Fiat Croma 1.6 i.e. and Lancia Delta II 1.6 i.e., the 159 A4.000 w…
Production years 1987–1990 meet Euro 0 standards; 1991–1995 models comply with Euro 1 (EU Directive 91/441/EEC). Vehicle-specific compliance confirmed via EU type approval records.
The Fiat 159 A4.000 – Petrol is a 1,586 cc inline-four SOHC engine developed for mid-size hatchbacks and sedans (1987–1995). It replaces carburetion with Magneti Marelli electronic fuel injection to improve emissions and throttle response. Designed for the Type 159 platform, it meets early Euro emissions standards while maintaining serviceability.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,586 cc | |
Fuel type | Petrol (Unleaded RON 95) | |
Configuration | Inline-4, SOHC, 8-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 80.0 mm × 79.0 mm | |
Power output | 57 kW (78 PS) @ 5,600 rpm | |
Torque | 120 Nm @ 3,200 rpm | |
Fuel system | Magneti Marelli IAW 1AV electronic fuel injection | |
Emissions standard | Euro 0 (1987–1990); Euro 1 (1991–1995) | |
Compression ratio | 9.4:1 | |
Cooling system | Water-cooled | |
Turbocharger | Not applicable | |
Timing system | Toothed belt (SOHC) | |
Oil type | SAE 10W-40, API SG/CC | |
Dry weight | 106 kg |
The Fiat 159 A4.000 – Petrol was used across Fiat's Type 159 platform with transverse mounting and front-wheel drive. This engine received platform-specific adaptations—lambda sensor calibration differences for Lancia Delta II—and from 1991, the facelifted Fiat Croma models adopted the revised hydraulic tappets, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The 159 A4.000 – Petrol's primary reliability risk is hydraulic tappet wear on early builds, with elevated incidence in vehicles with irregular maintenance. Internal Fiat service reports from 1990 indicated a significant portion of pre-1991 engines required tappet replacement before 90,000 km, while historical EU field data shows lambda sensor-related emissions failures were common in high-mileage units. Extended service intervals and poor-quality fuel amplify wear, making adherence to maintenance schedules and fuel quality critical.
Analysis derived from Fiat technical bulletins (1987-1995) and European Commission field reliability reports (1988-1996). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The 159 A4.000 – Petrol is mechanically simple and can be reliable with consistent maintenance. However, early models (1987–1991) are prone to hydraulic tappet wear if oil changes are delayed. Later units with the revised tappets (post-1991) show improved durability. Using correct SAE 10W-40 oil and regular lambda sensor inspection are essential for long-term reliability.
The most documented issues are hydraulic tappet wear (especially pre-1991), lambda sensor degradation, coolant leaks from the head gasket, and ignition timing drift due to distributor wear. These are confirmed in Fiat service bulletins and owner maintenance records from the era.
The 159 A4.000 – Petrol was used in the Fiat Croma 1.6 i.e. (1987–1991), Tempra 1.6 i.e. (1990–1995), and Lancia Delta II 1.6 i.e. (1989–1993). It was not shared with other Fiat Group models outside the Type 159 platform.
Limited tuning potential exists. Output can be modestly increased via ECU remapping, performance air filters, and exhaust upgrades, typically gaining 5–8 kW. The stock internals are not designed for forced induction. Any modifications should preserve reliability, as the engine's strength lies in simplicity and economy.
In the Fiat Tempra 1.6 i.e., fuel consumption is approximately 8.4 L/100km (city) and 6.0 L/100km (highway), equating to about 33 mpg UK combined. Real-world economy depends heavily on driving conditions and maintenance state. Well-tuned examples can achieve up to 37 mpg UK in steady highway driving.
Yes. The 159 A4.000 – Petrol is an interference engine. If the timing belt fails or jumps, the pistons can contact the valves, resulting in severe internal engine damage. Strict adherence to the 60,000 km belt replacement interval is critical to prevent catastrophic failure.
Fiat specifies SAE 10W-40 mineral oil meeting API SG/CC standards. Modern API SN/CK-4 oils are acceptable if they meet viscosity requirements. Oil should be changed every 10,000 km to protect the valvetrain, especially in pre-1991 models with early tappet designs.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
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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.
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