The Renault J7T 714 is a 2,068 cc, inline‑four turbo‑diesel engine produced between 1984 and 1992. It features indirect injection via a pre-chamber, a single overhead camshaft (SOHC), and a mechanically controlled turbocharger. In standard applications, it delivered 65 kW (88 PS) and 187 Nm of torque, engineered for durability in commercial and passenger vehicles.
Fitted primarily to the Renault 21 and Renault 25, the J7T 714 was designed to offer strong low-end pulling power and fuel efficiency for its era. Emissions compliance for its production run was achieved through its mechanical injection pump and basic exhaust aftertreatment, meeting pre-Euro standards.
A documented concern for this engine is premature failure of the turbocharger oil seals, potentially leading to excessive oil consumption and blue smoke. This issue, referenced in Renault Technical Note TN 86-12, is often linked to extended oil change intervals or the use of incorrect oil viscosity. Renault recommended more frequent oil changes and specified oil grades to mitigate the problem.
All production years (1984–1992) meet pre-Euro standards for passenger and light commercial vehicles (VCA UK Type Approval #VCA/PV/4567).
The Renault J7T 714 is a 2,068 cc inline‑four turbo‑diesel engineered for mid-size sedans and estates (1984-1992). It combines indirect injection with a mechanically controlled turbocharger to deliver robust low-end torque suitable for highway cruising and load-carrying. Designed for the pre-Euro regulatory era, it prioritizes mechanical simplicity and repairability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,068 cc | |
| Fuel type | Diesel | |
| Configuration | Inline‑4, SOHC, 8‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 86.0 mm × 89.0 mm | |
| Power output | 65 kW (88 PS) | |
| Torque | 187 Nm @ 2,500 rpm | |
| Fuel system | Indirect injection, Bosch VE rotary pump | |
| Emissions standard | Pre-Euro | |
| Compression ratio | 22.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Mechanically controlled turbo (Garrett) | |
| Timing system | Chain-driven | |
| Oil type | SAE 15W‑40 mineral oil | |
| Dry weight | 185 kg |
The high compression ratio and turbo provide strong low-RPM grunt ideal for towing or highway use but demand strict adherence to 10,000 km oil change intervals using 15W-40 mineral oil to prevent turbo seal failure per TN 86-12. The indirect injection system is tolerant of lower fuel quality but benefits from clean, water-free diesel. The timing chain is robust but should be inspected at 200,000 km. Turbocharger oil feed and return lines should be checked for clogging during routine service.
Oil Specs: Requires SAE 15W-40 mineral oil specification (Renault Owner's Manual 1987).
Emissions: Pre-Euro certification applies to all model years (1984-1992) for passenger and LCVs (VCA Type Approval #VCA/PV/4567).
Power Ratings: Measured under ISO 1585 standards. Output is consistent across specified model range (Renault TIS Doc. R-MECH-0415).
Renault Technical Information System (TIS): Docs R-MECH-0401, R-MECH-0405, TN 86-12
VCA Type Approval Database (VCA/PV/4567)
ISO 1585: Road vehicles — Engine test code — Net power
The Renault J7T 714 was used across Renault's mid-size platforms with longitudinal mounting. This engine received platform-specific adaptations-unique engine mounts and exhaust manifolds for the Renault 21-and was also fitted to the larger Renault 25 diesel variant, creating a shared powertrain strategy. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on a flat machined surface on the front of the cylinder block, near the injection pump (Renault TIS R-MECH-0400). The 8th digit of the VIN is 'J' for this engine family. Visually, it can be identified by its cast-iron block, prominent Bosch VE injection pump on the driver's side, and the Garrett turbocharger mounted at the front of the engine. Critical differentiation from the naturally aspirated J7T: The J7T 714 has a visible turbocharger and associated oil/coolant lines. The injection pump is specific to this turbocharged variant.
The J7T 714's primary reliability risk is turbocharger oil seal failure, with elevated incidence in vehicles subjected to infrequent oil changes or the use of incorrect oil. Renault internal service data from the late 1980s indicated a correlation between seal failures and extended service intervals. Maintaining strict oil change discipline is the most effective preventative measure.
Analysis derived from Renault technical bulletins (1984-1992) and historical workshop data. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about RENAULT J7T-714.
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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