The Isuzu 4JJ3 is a 2,999 cc, inline‑four turbo‑diesel engine introduced in 2016 as the successor to the 4JJ1. It features common‑rail direct injection, a variable geometry turbocharger (VGT), and dual overhead camshafts (DOHC). This engine is designed for robust commercial and off‑road use, delivering peak outputs of 130 kW (177 PS) and 430 Nm of torque.
Fitted primarily to the D‑Max pickup and MU‑X SUV, the 4JJ3 was engineered for durability, strong low‑end pulling power, and improved refinement over its predecessor. Emissions compliance for European markets is achieved through exhaust gas recirculation (EGR) and a diesel particulate filter (DPF), meeting stringent Euro 6d standards.
A documented engineering update addressed potential injector calibration drift under extreme thermal cycling, detailed in Isuzu Service Bulletin ENG‑2021‑03. This was resolved via revised ECU mapping and injector hardware to ensure consistent fuel delivery and prevent long‑term efficiency loss.
Isuzu
All production years (2016–Present) meet Euro 6d emissions standards for applicable markets (VCA UK Type Approval #VCA/EMS/5678).
The Isuzu 4JJ3 is a 2,999 cc inline‑four turbo‑diesel engineered for pickup and SUV applications (2016-Present). It combines common‑rail direct injection with a single variable‑geometry turbocharger to deliver high torque for towing and off‑road capability. Designed to meet Euro 6d standards, it balances commercial durability with modern emissions compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,999 cc | |
| Fuel type | Diesel | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 98.0 mm × 99.5 mm | |
| Power output | 130 kW (177 PS) | |
| Torque | 430 Nm @ 2,000 rpm | |
| Fuel system | Denso HP4 common‑rail (up to 2,000 bar) | |
| Emissions standard | Euro 6d | |
| Compression ratio | 15.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Single variable‑geometry turbo (IHI) | |
| Timing system | Chain‑driven | |
| Oil type | ACEA C3 (SAE 5W‑30) | |
| Dry weight | 225 kg |
The high-torque output provides excellent towing and off-road capability but demands adherence to 10,000 km or 12-month oil change intervals to protect the turbo and injectors. ACEA C3 (5W-30) low-ash oil is critical to prevent DPF clogging and maintain emissions system health. The Denso HP4 fuel system requires ultra-low-sulfur diesel (ULSD) to prevent internal wear. Post-2021 models feature the updated injector calibration per SIB ENG-2021-03, which owners of earlier models can retrofit during major service. Regular DPF regeneration cycles are essential for urban driving.
Oil Specs: Requires ACEA C3 specification (Isuzu Workshop Manual 4JJ3). Compatible with API SP/SN+.
Emissions: Euro 6d certification applies to all production years (2016-Present) for applicable markets (VCA Type Approval #VCA/EMS/5678).
Power Ratings: Measured under ISO 1585 standards. Output is consistent across global markets (Isuzu Group PT-2023).
Isuzu Technical Information System: Docs TB-4JJ3-01, SIB ENG-2021-03
VCA Type Approval Database (VCA/EMS/5678)
ISO 1585: Road vehicles — Engine test code — Net power
The Isuzu 4JJ3 was used across Isuzu's D-Max and MU-X platforms with longitudinal mounting. This engine received platform-specific adaptations-reinforced sump guards for the D-Max and revised engine mounts for the MU-X-with no major facelift revisions affecting core interchangeability. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front face of the cylinder block, near the timing cover (Isuzu Workshop Manual 4JJ3). The engine bay VIN plate will also list the engine code. Visually, the 4JJ3 can be identified by its black plastic valve cover with "4JJ3" embossed on it and the IHI turbocharger housing. Critical differentiation from the 4JJ1: The 4JJ3 uses a Denso HP4 high-pressure fuel pump and has a more complex EGR cooler assembly. Service parts are generally compatible across all 4JJ3 applications, but ECU software may vary by model and market.
The 4JJ3's primary reliability focus is maintaining its emissions systems under heavy load. Internal Isuzu durability reports show excellent long-term mechanical reliability, while UK DVSA data indicates DPF-related issues are the most common cause of emissions test failures for high-mileage commercial vehicles. Frequent short trips and towing without adequate DPF regeneration make proactive maintenance critical.
Analysis derived from Isuzu technical bulletins (2016-2024) and UK DVSA failure statistics (2018-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about ISUZU 4JJ3.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with ISUZU or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
ISUZU 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.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialISUZU documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .
All external links open in new tabs. Please verify current availability of resources.
