The Renault J7T 715 is a 2,068 cc, inline‑four naturally aspirated diesel engine produced between 1984 and 1992. It features a cast-iron block, indirect injection via pre-chambers, and a single overhead camshaft. Delivering 51 kW (69 PS), its robust construction prioritized durability and fuel economy over performance.
Fitted primarily to the Renault 25 and Renault 21, the J7T 715 was engineered for economical long-distance cruising and fleet applications. Emissions compliance for its era was managed through basic oxidation catalysts, meeting French and European standards of the mid-1980s.
One documented concern is premature failure of the mechanical fuel injection pump drive coupling, as noted in Renault Technical Note NT J7T‑01. This issue is often linked to extended service intervals or use of incorrect lubricants. Subsequent revisions introduced a reinforced coupling material to improve reliability under sustained load.
All production years (1984–1992) meet applicable French and European emissions standards for their production year (No VCA UK Type Approval applicable for this era).
The Renault J7T 715 is a 2,068 cc inline‑four naturally aspirated diesel engineered for executive sedans (1984-1992). It combines indirect injection with SOHC valvetrain to deliver dependable, economical performance. Designed to meet contemporary French and European emissions standards, it prioritizes longevity and fuel efficiency over power output.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,068 cc | |
| Fuel type | Diesel | |
| Configuration | Inline‑4, SOHC, 8‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 86.0 mm × 89.0 mm | |
| Power output | 51 kW (69 PS) | |
| Torque | 132 Nm @ 2,500 rpm | |
| Fuel system | Bosch VE mechanical injection with indirect pre-chamber | |
| Emissions standard | French/European standards (pre-Euro) | |
| Compression ratio | 22.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain | |
| Oil type | SAE 15W-40 mineral oil | |
| Dry weight | 185 kg |
The indirect injection system provides exceptional fuel tolerance and mechanical simplicity but requires strict 10,000 km oil change intervals to prevent sludge buildup. Use of correct SAE 15W-40 mineral oil is critical for lubricating the mechanical injection pump. The fuel pump drive coupling is a known wear item; replacement every 100,000 km or at timing chain service is recommended per Renault NT J7T-01. Glow plug system must be fully functional for reliable cold starts below 5°C.
Oil Specs: Requires SAE 15W-40 mineral oil (Renault SIB J7T-02). API CC specification minimum.
Emissions: Pre-dates formal Euro standards. Complied with French Decree 84-1043 and equivalent European directives.
Power Ratings: Measured under DIN 70020 standards. Output consistent across all markets (Renault TIS Doc. J7T-003).
Renault Technical Information System (TIS): Docs J7T-001, J7T-002, J7T-003, SIB J7T-01
French Journal Officiel Decree 84-1043 (Emissions)
DIN 70020: Road vehicles — Engine power measurement
The Renault J7T 715 was developed for Renault's 25 and 21 platforms with longitudinal mounting. This engine received platform-specific adaptations-reinforced engine mounts for the 25-and no significant facelift revisions affecting core compatibility during its production run. The engine was exclusive to Renault Group vehicles. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the flat machined pad on the left side of the cylinder block, adjacent to the injection pump (Renault TIS J7T-ID). The 8th VIN digit typically corresponds to engine displacement ('7' for 2.1L). Visually, the engine is identifiable by its cast-iron block, single cam cover, and prominent Bosch VE injection pump mounted on the right side. Critical differentiation from later F8M engines: J7T uses indirect injection with pre-chambers and a mechanical pump, whereas F8M uses direct injection. Service parts for fuel system are not interchangeable.
The J7T 715's primary reliability risk is fuel pump drive coupling failure, with elevated incidence in vehicles exceeding 100,000 km without replacement. Renault internal service data indicates this is a leading cause of sudden engine shutdown complaints, while owner club surveys show glow plug relay failures are common in cold climates. Extended service intervals make adherence to recommended maintenance critical.
Analysis derived from Renault technical bulletins (1984-1992) and Renault 21/25 owner club technical surveys. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about RENAULT J7T-715.
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RENAULT Official Site
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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)
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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.
GOV.UK: Vehicle Approval
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