The Fiat 834 B.048 is a 1,581 cc, inline‑four naturally aspirated petrol engine produced between 1985 and 1992. It features a single overhead camshaft (SOHC) design with two valves per cylinder and a carburettor fuel system. This configuration prioritizes simplicity and ease of maintenance, delivering 55 kW (75 PS) and 125 Nm of torque for light — duty applications.
Fitted primarily to the Fiat Uno and Regata, the 834 B.048 was engineered for economical urban driving and d…

Production years 1985–1992 pre-date formal Euro standards .
The Fiat 834 B.048 is a 1,581 cc inline‑four naturally aspirated petrol engineered for compact passenger vehicles (1985-1992). It combines a simple SOHC valvetrain with carburettor fuel delivery to deliver economical, low-stress performance for city driving. Designed for pre-Euro compliance, it prioritizes mechanical simplicity and ease of repair.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,581 cc | |
Fuel type | Petrol | |
Configuration | Inline‑4, SOHC, 8‑valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 80.0 mm × 78.5 mm | |
Power output | 55 kW (75 PS) @ 5,800 rpm | |
Torque | 125 Nm @ 3,000 rpm | |
Fuel system | Weber twin-choke carburettor | |
Emissions standard | Pre-Euro | |
Compression ratio | 9.5:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Belt-driven camshaft | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 115 kg |
The Fiat 834 B.048 was used across Fiat's compact passenger platforms with transverse mounting. This engine received platform-specific adaptations-unique engine mounts and ancillary brackets for the Uno vs. Regata-but no major facelift revisions occurred during its production, ensuring broad parts interchangeability. All adaptations are documented in OEM technical bulletins.
Engine Finders UK Ltd, which operates EngineCode.uk, can pass your enquiry to engine suppliers in the UK. The service is for vehicles in the United Kingdom, with UK delivery or fitting. This is a commercially connected service, and sending an enquiry does not confirm diagnosis or compatibility.
Diagnostic reminder: If a technician has recommended replacing the engine, you can send an enquiry to engine suppliers in the UK. Confirm the diagnosis first: an engine-code record does not diagnose a fault.
The 834 B.048's primary reliability risk is timing belt failure due to tensioner wear, with elevated incidence following neglected service intervals. Fiat workshop data indicates this is the most common major repair for high-mileage units, while its simple mechanical design otherwise offers excellent longevity. Neglecting the 60,000 km belt change makes proactive inspection critical.
Analysis derived from manufacturer technical service bulletins and industry workshop records. 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 834 B.048 is renowned for its mechanical simplicity and potential for very high mileage, often exceeding 200,000 km with basic care. Its main weakness is the timing belt and tensioner, which must be replaced strictly at 60,000 km intervals. Avoiding this service will almost certainly lead to catastrophic engine failure.
The most critical issue is timing belt failure due to worn tensioners. Other common problems include carburettor issues (clogging, leaks), ignition system faults (distributor, plugs, leads), and oil leaks from aged gaskets and seals. These are well-documented in Fiat service literature.
This engine was used in the Fiat Uno (146 series, 1985-1992) and Fiat Regata (138 series, 1985-1990), typically badged as the 1.6 i.e. in both models.
Minor tuning is possible via carburettor jetting, ignition timing, and exhaust upgrades. Significant power gains are limited by the SOHC 8-valve head design. Adding a turbocharger is a complex, non-OEM modification not recommended for reliability.
Fuel economy is reasonable for its era. In a typical Fiat Uno, expect around 7.0-8.0 L/100km (35-40 mpg UK) combined, depending heavily on driving style and condition of the carburettor.
Yes. The Fiat 834 B.048 is an interference engine. If the timing belt fails, the pistons will collide with the open valves, causing severe internal damage requiring a costly rebuild.
It requires a 10W-40 mineral oil meeting API SF specifications. Modern API SN or SP 10W-40 oils are backward compatible and perfectly suitable for this engine.
Comprehensive technical documentation and regulatory references
EngineCode.uk is operated by Engine Finders UK Ltd. It provides engine-reference information and an optional commercial enquiry service. It is not an official manufacturer website. Check the record's sources and confirm vehicle-specific details before relying on it for parts, repairs or replacement.
Our editorial standard prioritises relevant manufacturer documentation and official regulatory sources. The sources and verification status for a record should be checked alongside the data.
A statement is not verified merely because a source is listed. Where supporting evidence is missing or conflicting, the record should identify that limitation. Please report unsupported or inconsistent information.
Transparency in gaps
A missing or unverified value does not mean the manufacturer has withheld it. We distinguish information not yet verified, information not available to us, and information explicitly not disclosed by the source.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
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.
Records are subject to review and correction. Source links, dates and verification notes should be read with the technical information. Our Editorial and Sourcing Policy explains our standards and review process.
Found an error or missing source? Report a problem with this page. Include the field or statement concerned and a supporting source if available. You can also email corrections@enginecode.uk.
Copyright and permissions
Images and other material may be protected by copyright. Attribution does not by itself grant permission to reuse material. If you believe material on this site infringes your rights, contact copyrights@enginecode.uk with the page URL and details of your claim. We will review the material and take appropriate action.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
Our Privacy Policy explains how Engine Finders UK Ltd uses information from visits, vehicle lookups, enquiries and messages. Our Cookie Policy explains cookies and similar technologies and how to change your choices.
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.
Ownership and commercial services
EngineCode.uk is owned and operated by Engine Finders UK Ltd. Alongside our reference content, we offer an optional replacement-engine enquiry service through Engine Finders and may identify relevant services provided by businesses connected with us. These commercial connections are disclosed. Using an enquiry service is not required to read our reference content.
Engine Finders UK Ltd operates this website. Our optional enquiry service has a commercial purpose. Our Ownership and Commercial Disclosure explains the relationship between the reference website and that service. Participating suppliers pay a fee or subscription to participate on the network and receive quote requests.
Use this record as a starting point for identification. Specifications and vehicle applications may contain errors or omissions. Confirm the exact engine variant and compatibility using vehicle-specific documentation and a qualified supplier or technician.
All external links open in new tabs. Please verify current availability of resources.