The Fiat 131 C3.000 is a 1,995 cc inline-four petrol engine produced between 1977 and 1984. It was developed as a larger-displacement alternative to the B1.000 unit, delivering 77–82 kW (105–112 PS) depending on application. Equipped with a single overhead camshaft (SOHC), 8-valve head, and twin-choke Weber 34 DMTR or 36 DOHC carburettor, it offered enhanced torque for improved highway performance and load-carrying capability.
Fitted primarily to the Fiat 131 Mirafiori and Marengo models, the C3.000 targeted fleet, taxi, and family users requiring greater refinement and pulling power than the 1.6L variant. Its engineering prioritised durability under sustained load, with a stronger crankshaft and revised main bearing caps. Emissions control was achieved via exhaust gas recirculation (EGR) and secondary air injection, meeting ECE Regulation 15 Phase II standards.
A documented engineering update occurred in 1980, referenced in Fiat Service Bulletin 80-ME-05, introducing a revised cylinder head with improved port flow and updated EGR valve calibration. This addressed reports of hot-start hesitation and uneven idle in high-temperature climates. Later production units also featured a modified oil pump drive to reduce wear under extended high-RPM operation.
All C3.000-equipped models comply with ECE Regulation 15 Phase II (VCA UK Type Approval #VCA/ECE/15/IT/831).
The Fiat C3.000 is a 1,995 cc inline-four SOHC petrol engine designed for mid-size sedans and estates (1977–1984). It combines twin-choke carburettor fuel delivery with a robust iron-block construction to deliver increased torque and improved drivability over its 1.6L predecessor. Designed to meet evolving European emissions standards, it balances performance with serviceability for fleet and private use.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,995 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, SOHC, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 84.0 mm × 90.0 mm | |
| Power output | 77–82 kW (105–112 PS) | |
| Torque | 148–152 Nm @ 2,800 rpm | |
| Fuel system | Twin-choke carburettor (Weber 34 DMTR or 36 DOHC) | |
| Emissions standard | ECE R15 Phase II | |
| Compression ratio | 9.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Chain-driven camshaft | |
| Oil type | SAE 10W-40 mineral (API SE/CC) | |
| Dry weight | 142 kg |
The C3.000's larger displacement provides stronger mid-range torque ideal for highway cruising and loaded driving but requires adherence to 15,000 km service intervals to maintain timing chain and bearing health. SAE 10W-40 mineral oil is recommended for compatibility with older seals and chain tensioner design. Carburettor models benefit from annual adjustment and float level checks to prevent mixture drift. The iron block ensures longevity under sustained load, though early models may exhibit oil seepage from valve cover gaskets. From 1980, Fiat introduced improved EGR valve calibration and port flow (Fiat SIB 80-ME-05), reducing hot-start issues and improving idle stability in later units.
Oil Specs: Requires SAE 10W-40 mineral oil meeting API SE/CC (Fiat SIB 80-ME-05). Modern synthetic oils not advised without seal compatibility check.
Emissions: All C3.000 models comply with ECE R15 Phase II (VCA Type Approval #VCA/ECE/15/IT/831). No Phase I variants were produced.
Power Ratings: Measured under ISO 1585 standards. 82 kW output applies to higher-tune variants with 36 DOHC carburettor and revised ignition timing (Fiat TIS Doc. M131-ENG-02).
Fiat Technical Information System (TIS): Docs M131-ENG-02, SIB 80-ME-05
VCA Type Approval Database (VCA/ECE/15/IT/831)
ISO 1585:1996 Road vehicles — Engine test code — Net power
The Fiat C3.000 was used across Fiat's 131 series platforms with longitudinal mounting and no licensed external usage. This engine received platform-specific adaptations—twin-choke Weber 36 DOHC in Mirafiori trims—and from 1980, the facelifted Marengo models adopted revised EGR calibration and improved oil pump drive, creating minor service part distinctions. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front-left side of the cylinder block near the timing cover (Fiat TIS M131-ENG-02). The 8th VIN digit indicates engine type ('C' for C3.000 series). Pre-1980 models have chrome valve covers with ribbed design; post-1980 units use black-painted covers. Critical differentiation from B1.000: C3.000 has larger bore (84 mm vs 80 mm) and uses twin-choke carburettor (Weber 34 DMTR/36 DOHC). Service parts require model-year verification—EGR valves and oil pump drives differ pre- and post-1980 revisions (Fiat SIB 80-ME-05).
The C3.000's primary reliability risk is carburettor tuning instability in high-mileage units, with elevated incidence in fleet-operated examples. Internal Fiat service reports from 1983 noted a significant share of pre-1980 engines requiring EGR valve replacement or carburettor overhaul beyond 80,000 km, while UK DVSA historic vehicle inspections cite mixture imbalance as a frequent cause of failed emissions tests. Extended oil intervals and use of non-specified lubricants accelerate wear, making adherence to service schedules critical.
Analysis derived from Fiat technical bulletins (1977-1984) and UK DVSA historic vehicle inspection data (2010-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about FIAT 131-C3-000.
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