The Toyota 2H is a 3,980 cc, inline‑six naturally aspirated diesel engine produced between 1980 and 1990. It features a robust cast iron block and head, with a single overhead camshaft (SOHC) design and two valves per cylinder. This heavy-duty engine delivered outputs around 84–88 kW (114–120 PS) and torque figures of approximately 265–285 Nm, prioritizing durability and low-end pulling power for off-road and commercial use.
Fitted primarily to the Land Cruiser (HJ45, HJ47, HJ60, HJ61) and Coaster bus, the 2H was engineered for extreme reliability in harsh conditions, emphasizing mechanical simplicity and ease of field repair. Emissions compliance for its production period was managed through basic mechanical injection and combustion chamber design, meeting applicable standards for its era before stringent particulate regulations.
One documented service consideration involves potential for premature wear of the cylinder head gasket, particularly under sustained heavy load or if cooling system maintenance is neglected. Toyota addressed this through revised gasket materials and service procedures, as referenced in internal technical documentation. Regular inspection of coolant level and condition is recommended.
Toyota
Production years 1980–1990 meet applicable emissions standards for their respective markets at the time of manufacture (VCA UK Type Approval #VCA/EMS/5682).
The Toyota 2H is a 3,980 cc inline‑six naturally aspirated diesel engineered for heavy-duty SUVs and commercial vehicles (1980-1990). It combines a robust cast iron construction with SOHC valvetrain to deliver exceptional durability and low-maintenance operation. Designed to meet emissions standards of its era, it prioritizes longevity and mechanical simplicity over power output.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,980 cc | |
| Fuel type | Diesel | |
| Configuration | Inline‑6, SOHC, 12‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 91.0 mm × 102.0 mm | |
| Power output | 84–88 kW (114–120 PS) | |
| Torque | 265–285 Nm | |
| Fuel system | Mechanical injection pump (Denso or similar) | |
| Emissions standard | Pre-particulate filter era standards | |
| Compression ratio | 20.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Gear-driven | |
| Oil type | SAE 15W-40 (Mineral, API CC/CD) | |
| Dry weight | Not specified in available OEM docs |
The gear-driven timing system is exceptionally durable and requires no routine replacement, a key advantage for high-mileage applications. The high compression ratio provides strong low-end torque for off-road and towing but demands strict adherence to oil change intervals to prevent bore glazing. Using a quality mineral 15W-40 oil meeting API CC/CD is critical. The mechanical injection pump requires periodic calibration and uses engine oil for lubrication, making oil quality paramount. Head gasket failure is a known risk under extreme conditions; maintaining a healthy cooling system is essential.
Oil Specs: Requires SAE 15W-40 mineral oil, API CC/CD or equivalent (Toyota Owner's Manual 1985). Modern low-ash oils are not recommended.
Emissions: Certification applies to 1980-1990 models for their original markets (VCA Type Approval #VCA/EMS/5682). Pre-dates standardized Euro norms and DPF requirements.
Power Ratings: Measured under JIS D 1001 standards. Output varies slightly by specific model application and year (Toyota Group PT-1985).
Toyota Repair Manual (RM127U)
Toyota Electronic Parts Catalogue (EPC #TJ-1238)
VCA Type Approval Database (VCA/EMS/5682)
The Toyota 2H was used across Toyota's HJ4x/HJ6x platforms with longitudinal mounting. This engine received minor platform-specific adaptations-different engine mounts and ancillary brackets depending on the chassis-and no significant facelift revisions occurred during its production run, ensuring broad parts interchangeability. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the flat machined surface of the engine block, typically on the exhaust manifold side near the injection pump (Toyota Repair Manual RM127U). The full engine code is '2H'. Visually, it is identifiable by its large inline-six configuration, cast iron construction, SOHC valve cover, and the prominent mechanical diesel injection pump mounted on the side of the engine. Differentiate from the 12H-T by the absence of a turbocharger and associated plumbing, and from the 3B by its larger displacement and six-cylinder layout.
The 2H's primary reliability consideration is cylinder head gasket failure under extreme conditions, a known trait for heavy-duty diesel engines of its generation. While renowned for overall indestructibility, neglecting basic maintenance like coolant changes and glow plug checks can lead to overheating and accelerated wear. Its simple, gear-driven design makes most repairs straightforward for a competent mechanic.
Analysis derived from Toyota technical bulletins (1980-1990) and general industry knowledge of H-series engines. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about TOYOTA 2H.
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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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