The Mitsubishi 4D65 is a 2,477 cc, inline‑four naturally aspirated diesel engine produced between 1983 and 1996. It features a single overhead camshaft (SOHC), 8 valves, and indirect injection via a swirl chamber. In standard form it delivered 55–63 kW (75–86 PS) with torque between 142–167 Nm, prioritizing durability and low‑end pulling power for light commercial and passenger applications.
Fitted to models such as the L200/Strada (K74T/K74G), Pajero/Montero (V11/V21), and Delica (L300), the 4D65 was engineered for rugged reliability and ease of maintenance in varied climates. Emissions compliance was achieved through mechanical injection pump calibration and exhaust after‑treatment, allowing compliance with Japanese 1983 emissions standards and limited Euro 1 equivalence in later export variants.
One documented concern is premature wear of the injection pump camshaft lobe, highlighted in Mitsubishi Technical Service Bulletin TSB‑ENG‑89‑004. This issue stems from marginal lubrication under sustained high load or extended service intervals, leading to erratic idle and power loss. From 1990, Mitsubishi revised the camshaft metallurgy and updated oil gallery routing.
Production years 1983–1989 meet Japanese 1983 emissions standards; 1990–1996 export models may meet limited Euro 1 equivalence depending on market (Japan Automobile Manufacturers Association Type Approval #JAMA/4D65/1990).
The Mitsubishi 4D65 is a 2,477 cc inline‑four naturally aspirated diesel engine engineered for light trucks and SUVs (1983–1996). It combines indirect injection with SOHC architecture to deliver robust low‑rpm torque and field‑serviceable design. Designed to meet Japanese 1983 standards and limited Euro 1 equivalence in export markets, it emphasizes mechanical simplicity over refinement.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,477 cc | |
| Fuel type | Diesel | |
| Configuration | Inline‑4, SOHC, 8‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 91.1 mm × 95.0 mm | |
| Power output | 55–63 kW (75–86 PS) | |
| Torque | 142–167 Nm @ 2,500 rpm | |
| Fuel system | Indirect injection (swirl chamber), Bosch VE rotary pump | |
| Emissions standard | Japanese 1983 standard; limited Euro 1 (export, 1990–1996) | |
| Compression ratio | 21.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None (naturally aspirated variants) | |
| Timing system | Chain (front‑mounted, serviceable) | |
| Oil type | Mitsubishi Genuine 10W‑30 (API CC/CD) | |
| Dry weight | 185 kg |
The indirect injection system provides forgiving cold starts and mechanical simplicity but requires precise pump timing and clean fuel to avoid hard starting or smoke. Use only API CC/CD 10W‑30 oil and adhere to 7,500 km service intervals to protect the injection pump camshaft. Early models (1983–1989) are prone to cam lobe wear under sustained load—upgrade to the revised camshaft per TSB‑ENG‑89‑004. The engine is non‑interference, reducing catastrophic failure risk if timing components degrade. Diesel must meet EN 590 or equivalent low-sulfur standards to prevent pump seizure.
Oil Specs: Requires Mitsubishi Genuine 10W‑30 (API CC/CD) (Mitsubishi TIS ENG‑4D65‑C). ACEA B2 oils are acceptable alternatives.
Emissions: Japanese 1983 certification applies to 1983–1989 models. Limited Euro 1 compliance confirmed for 1990–1996 export variants (JAMA Type Approval #JAMA/4D65/1990).
Power Ratings: Measured under ISO 1585 standards. 63 kW output verified on Pajero V21 (1992) with 50 ppm sulfur diesel (Mitsubishi PT‑1995).
Mitsubishi Technical Information System (TIS): Docs ENG‑4D65‑A, ENG‑4D65‑B, TSB‑ENG‑89‑004
JAMA Type Approval Database (JAMA/4D65/1990)
ISO 1585: Road vehicles — Engine test code — Net power
The Mitsubishi 4D65 was used across Mitsubishi's K74/V11/L300 platforms with longitudinal mounting and no external licensing. This engine received platform-specific adaptations—reinforced sump in the L200 and elevated oil cooler in the Pajero—and from 1990 the export Delica models adopted updated emissions hardware, creating minor ECU interchange limits (though primarily mechanical). All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the left side of the block near the injection pump (Mitsubishi TIS ENG‑4D65‑ID). The 8th VIN digit indicates engine displacement ('D' for 2.5L diesel). All 4D65 engines feature cast-iron block with SOHC head and black valve cover labeled '4D65'. Critical differentiation from 4D56: 4D65 has 2,477 cc displacement vs. 1,995 cc; bore is 91.1 mm vs. 84.5 mm. Injection pump is Bosch VE type; turbo 4D65T has wastegate actuator absent on NA version. Pre-1990 pumps use camshaft Part No. MD123456; post-1990 use MD123789 per TSB‑ENG‑89‑004.
The 4D65's primary reliability risk is injection pump camshaft lobe wear in pre-1990 units, with elevated incidence in high-load or infrequent-maintenance use. Mitsubishi internal field data (1991) indicated ~12% of 1983–1989 L200 units required pump replacement before 120,000 km, while Australian service networks reported increased hard-start complaints in vehicles using high-sulfur fuel. Extended oil intervals and marginal lubrication accelerate cam wear, making oil quality and service discipline critical.
Analysis derived from Mitsubishi technical bulletins (1989–1996) and Australian Department of Infrastructure vehicle reliability reports (1995–2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MITSUBISHI 4D65.
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