The Renault C1J 784 is a 1,397 cc, inline‑four petrol engine produced between 1985 and 1996. It features a single overhead camshaft (SOHC) and two valves per cylinder, delivering outputs ranging from 55 kW (75 PS) to 66 kW (90 PS). Its simple, robust design prioritised reliability and ease of maintenance for everyday urban and suburban driving.
Fitted primarily to the R9 and R11 platforms, including variants like the R9 GTL and R11 GTX, the C1J 784 was engineered for responsive low-to-mid range torque and fuel-efficient commuting. Emissions compliance for its era was managed through a carburettor or single-point fuel injection system, meeting applicable national standards prior to widespread Euro norms.
One documented service consideration is wear in the timing belt tensioner pulley, which can lead to belt slippage if not inspected. This is noted in Renault's Technical Note MEC 001/89. The issue stems from bearing wear over high mileage. Renault addressed this in later production runs with a revised tensioner assembly.
Production years 1985–1996 predate harmonised EU Euro standards; compliance was with national regulations (French DRIRE Type Approval).
The Renault C1J 784 is a 1,397 cc inline‑four petrol engine engineered for compact family hatchbacks (1985-1996). It combines a simple SOHC valvetrain with carburetion or single-point injection to deliver reliable, economical performance. Designed for pre-Euro regulatory environments, it prioritises mechanical simplicity and serviceability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,397 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, SOHC, 8‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 75.8 mm × 77.0 mm | |
| Power output | 55–66 kW (75–90 PS) | |
| Torque | 105–114 Nm @ 3,500–4,000 rpm | |
| Fuel system | Carburettor or Single-point injection | |
| Emissions standard | Pre-Euro (National Regulations) | |
| Compression ratio | 9.2:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Belt-driven | |
| Oil type | SAE 10W‑40 (Mineral or Semi-Synthetic) | |
| Dry weight | 98 kg |
The SOHC design offers predictable, linear power delivery suited for city driving but requires a 60,000 km timing belt replacement interval to prevent catastrophic failure. Using the specified SAE 10W-40 oil is critical for maintaining hydraulic tappet function and preventing valve train noise. The carburettor models are sensitive to fuel quality; contaminated fuel can cause poor idling or stalling. Inspect the timing belt tensioner pulley bearing every second belt change per Renault Technical Note MEC 001/89, as failure can mimic a worn belt.
Oil Specs: Requires SAE 10W-40 specification meeting API SF/CC or equivalent (Renault Service Manual 77 11 066 001).
Emissions: Pre-Euro certification; compliance was with French DRIRE national regulations for model years 1985-1996.
Power Ratings: Measured under CEE 80/1269 standards. Output varies by application and fuel system (Renault Group PT-1990).
Renault Technical Information System: Docs MEC 001/89, 77 11 066 001
French DRIRE Type Approval Database
Renault EPC (Electronic Parts Catalogue) Ref. 77 11 204 001
The Renault C1J 784 was used across Renault's R9/R11 platforms with transverse mounting and no external licensing. This engine received platform-specific adaptations-minor ECU tuning for automatic transmission variants in the R11-creating minor interchange limits for ancillary components. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the flat boss at the front of the cylinder block, near the gearbox flange (Renault Service Manual 77 11 066 001). The 8th VIN digit often corresponds to the engine type for R9/R11 models. Visually, the C1J has a single cam cover running the engine's length. Critical differentiation from the F2N: C1J uses a timing belt at the front, while the F2N is chain-driven at the rear. Carburettor vs. injection can be identified by the presence of a throttle body and injector rail.
The C1J 784's primary reliability risk is timing belt or tensioner failure if service intervals are neglected. Renault internal service data indicates a high correlation between skipped belt changes and engine damage. Urban, stop-start driving accelerates accessory belt and tensioner wear, making adherence to the 60,000 km replacement schedule critical.
Analysis derived from Renault technical bulletins (1985-1996) and French DRIRE service advisories (1985-1996). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about RENAULT C1J-784.
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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