The Renault J8S 760 is a 2,068 cc, inline‑four naturally aspirated diesel engine produced between 1986 and 1990. It features a SOHC, 8‑valve design with indirect injection via pre‑combustion chambers, prioritising durability and fuel economy over peak performance. Output is 53 kW (72 PS) and 130 Nm, a modest increase over its predecessor, reflecting incremental efficiency improvements.
Fitted primarily to the Renault 21 Diesel and various commercial derivatives, the J8S 760 was engineered for dependable, economical operation in mid-size applications. Its character is defined by low‑revving torque and mechanical simplicity, making it suitable for steady highway driving and light load carrying. Emissions control was minimal, relying on basic engine tuning to meet prevailing national standards.
A primary documented concern is cylinder head cracking, particularly between valve seats, a carryover issue from the J8S 612 noted in Renault service documentation. This issue, stemming from the head's casting design and thermal stress, was partially addressed with minor material revisions but remained a known failure point. The engine was superseded by more advanced, turbocharged diesel units offering improved power and efficiency.
Production years 1986–1990 predate formal Euro emissions standards. Compliance was based on national regulations of the time (French DRIRE Type Approval).
The Renault J8S 760 is a 2,068 cc inline‑four naturally aspirated diesel engineered for mid‑size sedans and light commercial vehicles (1986-1990). It combines indirect injection with a simple SOHC valvetrain to deliver dependable, low‑maintenance operation. Designed for pre‑Euro regulatory environments, it prioritises longevity and economy over performance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,068 cc | |
| Fuel type | Diesel | |
| Configuration | Inline‑4, SOHC, 8‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 88.0 mm × 85.0 mm | |
| Power output | 53 kW (72 PS) @ 4,500 rpm | |
| Torque | 130 Nm @ 2,500 rpm | |
| Fuel system | Indirect injection (Bosch PES6A pump, pre‑chamber) | |
| Emissions standard | Pre‑Euro (National Standards) | |
| Compression ratio | 22.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain‑driven camshaft | |
| Oil type | Mineral 15W‑40 (CC/CD specification) | |
| Dry weight | Not available in source documentation |
The high compression ratio and indirect injection provide strong low-end torque ideal for steady cruising but demand strict cooling system maintenance to prevent cylinder head cracking. Mineral 15W-40 oil (CC/CD spec) is critical for its simple design and lack of modern filtration. Overheating is the primary cause of catastrophic failure; ensure thermostat and radiator function. Pre-chamber glow plugs require periodic inspection for cold-start reliability. Avoid high RPM operation; the engine is designed for low-speed durability.
Oil Specs: Requires mineral 15W-40 meeting API CC/CD or equivalent (Renault Tech. Manual 8100). Modern low-ash oils are not required.
Emissions: Pre-dates Euro standards. Compliance based on 1980s French national regulations (DRIRE).
Power Ratings: Measured under DIN 70020 standards. Output is net, as installed in vehicle (Renault Tech. Manual 8100).
Renault Technical Manual 8100 (Engine J8S)
Renault EPC (Electronic Parts Catalogue) Reference: J8S
French DRIRE Historical Type Approval Records
The Renault J8S 760 was used across Renault's R21 platform with longitudinal mounting. This engine received minor platform-specific adaptations in ancillary bracket positioning, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on a flat pad on the left-hand side of the engine block, near the fuel injection pump (Renault Tech. Manual 8100). The full code "J8S 760" should be clearly visible. Differentiate from the similar J8S 612 by production year (post-1986) and higher power output (72 PS vs 64 PS). The absence of a turbocharger is the most obvious visual identifier. Cylinder head casting number 7700659001 is specific to the 760 variant and shares the same cracking risk as the 612.
The J8S 760's primary reliability risk is cylinder head cracking, with elevated incidence following cooling system neglect. Renault internal service data from the late 1980s indicated this as the leading cause of major engine failure for this variant, while owner club surveys consistently cite overheating events as the precursor. Maintaining optimal coolant temperature and concentration is critical to prevent catastrophic engine damage.
Analysis derived from Renault technical bulletins (1986-1990) and aggregated owner club failure reports (1990-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about RENAULT J8S-760.
Comprehensive technical documentation and regulatory references
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RENAULT 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.
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