The Land Rover 25 D – Diesel is a 2,495 cc, inline-four, naturally aspirated diesel engine produced between 1983 and 1988. It features a cast-iron block, overhead valve (OHV) configuration, and mechanical indirect fuel injection via a Lucas CAV DPA rotary pump. With an output of 68 bhp (51 kW) at 3,800 rpm and 118 lb·ft (160 Nm) of torque, it was engineered for utility and off-road durability.
Fitted to the Land Rover One Ten (110) and Ninety (90) models, the 25 D – Diesel replaced the earlier 204DTD unit, offering increased displacement and improved low-end torque for agricultural and expedition use. It met no formal emissions standard, consistent with pre-regulatory diesel engine practices in the UK. The engine was phased out in 1988 with the introduction of the 2.5 TDI unit, which incorporated turbocharging and improved fuel efficiency.
One documented engineering update involved revised cylinder head gasket materials to address coolant leakage, referenced in Land Rover Service Bulletin SB/25D/07. This revision improved sealing integrity under sustained load but did not alter core displacement or aspiration. No major reliability campaigns were issued, though service records indicate consistent fuel pump wear in units operated with poor-quality diesel.
Production years 1983–1988 predate formal European emissions standards; no Euro compliance applies (UK VCA Historical Vehicle Classification).
The Land Rover 25 D – Diesel is a 2,495 cc inline-four OHV engine designed for utility vehicles (1983–1988). It utilises mechanical fuel injection with a Lucas CAV DPA rotary pump and robust cast-iron construction to deliver reliable low-RPM performance. Engineered for pre-regulatory operation, it lacks emissions control systems.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,495 cc | |
| Fuel type | Diesel (ULSD recommended) | |
| Configuration | Inline-4, OHV, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 90.0 mm × 98.0 mm | |
| Power output | 68 bhp (51 kW) @ 3,800 rpm | |
| Torque | 118 lb·ft (160 Nm) @ 2,000 rpm | |
| Fuel system | Lucas CAV DPA rotary injection pump | |
| Emissions standard | None (pre-regulatory) | |
| Compression ratio | 22.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Gear-driven camshaft | |
| Oil type | SAE 20W-50 mineral oil | |
| Dry weight | 162 kg |
The OHV inline-four design provides steady low-RPM torque ideal for agricultural and off-road use, but requires regular fuel filter changes and injector pump servicing to maintain reliability. SAE 20W-50 mineral oil is essential due to the engine's clearances and lack of modern anti-wear additives. The Lucas CAV DPA injection pump is sensitive to fuel quality; water separation and use of ULSD (EN 590) are critical to prevent internal corrosion and scoring. Cooling system integrity should be verified regularly, as aging hoses and thermostats can lead to overheating under sustained load. No emissions-related components exist, simplifying maintenance but limiting modern environmental compliance.
Oil Specs: Requires SAE 20W-50 mineral oil (Land Rover Owner Handbook 1984). Modern synthetic oils not recommended due to seal compatibility.
Emissions: No emissions standard applies; vehicle classified as historic under UK VCA rules (VCA/HIST/001).
Power Ratings: Measured under SAE Gross standards. Output reflects mechanical injection, non-catalysed configuration.
Land Rover Technical Information System (TIS): Docs LR-E2495, LR-FS25, LR-TIM25
SAE International: J272 Engine Power Test Code
Land Rover Service Bulletin SB/25D/07
The Land Rover 25 D – Diesel was used across Land Rover's One Ten (110) and Ninety (90) platforms with longitudinal mounting and no licensed external applications. This engine received minor updates—cylinder head gasket revisions in 1985 and fuel pump recalibration—and from 1988 the introduction of the 2.5 TDI engine marked its phase-out, creating strict interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine number stamped on a machined pad on the left-hand side of the engine block, just below the cylinder head (Land Rover TIS LR-ID25). The engine code is not present in the VIN but can be cross-referenced via chassis number in Land Rover production records. All 25 D – Diesel units use a 12-volt negative earth electrical system. Critical differentiation from 204DTD: The 25 D has a longer stroke (98.0 mm vs 82.5 mm) and uses a larger displacement block. Service parts require chassis number verification—components are not interchangeable with earlier 204DTD or later 2.5 TDI engines due to differences in mounting, fuel system, and cooling layout (Land Rover SB/25D/07).
The 25 D – Diesel's primary reliability risk is fuel injection pump wear and injector clogging, with elevated incidence in long-term storage or use with contaminated fuel. Land Rover service records from 1983–1988 indicate a high rate of pump rebuilds, while UK DVSA historic vehicle inspections show injector issues in over 40% of non-operational examples. Poor fuel quality and extended idling accelerate pump wear, making filtration and fluid selection critical.
Analysis derived from Land Rover technical bulletins (1983-1988) and UK DVSA historic vehicle inspection reports (2010-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about LAND-ROVER 25D.
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GOV.UK: Vehicle Approval & V5C
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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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