Types of RD28T Engines
The RD28T engine is a 2.8-liter inline 6-cylinder diesel engine equipped with a turbocharger, representing a significant variant of Nissan's straight-six diesel engine family. This powerful and reliable engine has been installed in numerous Nissan and Infiniti models, with particularly notable applications in the rugged Nissan Patrol and Safari off-road vehicles.
Engine Lineage: The RD28T belongs to Nissan's RD engine series, which was developed as a robust power solution for medium to large vehicles requiring significant torque and reliability in challenging conditions.
There are two main configurations of the Nissan RD28T engine, each with specific characteristics and applications:
RD28T I6 Engine
The standard and most common configuration featuring an inline 6-cylinder layout. This design is renowned for its naturally balanced operation and smooth power delivery.
- Design: DOHC with 60-degree cylinder angle
- Cylinder arrangement: Inline (1-2-3-4-5-6)
- Compression ratio: 19.0:1
- Primary applications: Nissan Patrol, Safari, and select Infiniti models
The turbocharger is strategically positioned between the exhaust and intake manifolds, enhancing combustion efficiency and power output without sacrificing reliability.
RD28T V6 Engine
A less common variant featuring a V6 cylinder configuration, designed for applications where engine bay space is more limited but significant power is still required.
- Design: DOHC with 60-degree V-configuration
- Cylinder arrangement: V-formation (1-2-3-4-5-6)
- Compression ratio: 19.0:1
- Primary applications: Nissan X-Trail, Qashqai, and select crossover vehicles
The V6 configuration offers a more compact footprint while maintaining the turbocharging benefits of increased power and efficiency compared to naturally aspirated engines.
Specifications & Maintenance of RD28T Engine
The RD28T engine is known for its durability and longevity when properly maintained. Following the recommended maintenance schedule is crucial for ensuring optimal performance and extending the engine's service life.
| Maintenance Task | Frequency | Importance | Special Notes |
|---|---|---|---|
| Engine Oil Change | Every 5,000 km | Critical | Use high-quality diesel-specific oil |
| Air Filter Replacement | Every 20,000 km | High | More frequently in dusty conditions |
| Coolant Flush | Every 100,000 km | High | Use manufacturer-recommended coolant |
| Timing Belt Inspection | Every 100,000 km | Critical | Replace if wear is visible |
| Fuel Filter Replacement | Every 30,000 km | High | Critical for diesel engines |
| Belts and Hoses Inspection | Quarterly | Medium | Replace at first sign of wear |
Essential Maintenance Procedures
Regular Oil Changes
Engine oil is vital for the RD28T, lubricating critical components to reduce friction and prevent premature wear. Fresh oil should be introduced every 5,000 kilometers using the manufacturer-recommended grade (typically 15W-40 or 5W-40 for diesel engines). This regular maintenance is the foundation of engine longevity.
Air Filter Replacement
The air filter is the first line of defense against contaminants entering your RD28T engine. Regular inspection and replacement every 20,000 kilometers (or more frequently in dusty environments) ensures proper air-fuel mixture and protects internal engine components from abrasive particles.
Coolant System Maintenance
The cooling system prevents the RD28T from overheating during operation. A complete coolant flush every 100,000 kilometers removes accumulated contaminants and scale that can reduce cooling efficiency. Always use the correct coolant specification to maintain proper temperature regulation and prevent corrosion.
Timing Belt Care
The timing belt synchronizes the crankshaft and camshaft rotation in the RD28T, ensuring precise valve timing. Regular inspection for cracks, fraying, or glazing is essential, with complete replacement recommended at 100,000 kilometers. Failure of this component can lead to catastrophic engine damage.
Fuel System Maintenance
The fuel filter prevents contaminants from reaching sensitive fuel system components. Replace this filter every 30,000 kilometers to maintain proper fuel flow and protect injectors. This is particularly important for diesel engines like the RD28T, as diesel fuel can contain more contaminants than gasoline.
Belts and Hoses Inspection
Regular examination of all auxiliary belts and coolant hoses for cracks, leaks, or deterioration helps prevent unexpected failures. Inspect these components quarterly and replace any showing signs of wear or damage to avoid roadside breakdowns.
Maintenance Tip: When servicing the RD28T engine, always use OEM or high-quality aftermarket parts designed specifically for turbocharged diesel applications. The additional heat and pressure created by the turbocharger system requires components capable of withstanding these enhanced stresses.
How to Choose an RD28T Engine
Selecting the appropriate RD28T engine requires careful consideration of multiple factors to ensure optimal performance, reliability, and cost-effectiveness for your specific application.
Vehicle Compatibility
The RD28T engine comes in different configurations designed for specific vehicle applications:
- Nissan Patrol/Safari: Requires the more robust I6 configuration to handle off-road demands
- Crossover Models: May accommodate the more compact V6 configuration
- Retrofitting: Consider mounting points, transmission compatibility, and electrical connections
Engine Condition Assessment
When evaluating a used RD28T engine, thoroughly examine:
- Mileage: Lower mileage typically indicates less internal wear
- Service History: Documentation of regular maintenance is a positive indicator
- Compression Test Results: All cylinders should show consistent pressure
- Turbocharger Condition: Check for shaft play or oil leakage
Key Selection Criteria
| Selection Factor | Considerations | Impact on Performance |
|---|---|---|
| Engine Variant | Standard RD28T vs. RD28T NEO (newer version) | NEO offers improved efficiency and emissions control |
| Power Requirements | Towing needs, vehicle weight, terrain type | Insufficient power leads to strain and reduced lifespan |
| Fuel Efficiency | Operating costs over engine lifetime | NEO variant typically offers 5-10% better efficiency |
| Parts Availability | Local market supply of components | Affects maintenance costs and vehicle downtime |
| Emissions Compliance | Local regulatory requirements | May limit options in regions with strict emissions standards |
Important Consideration: When purchasing a used RD28T engine, always verify that the engine number matches the seller's description. This helps confirm the engine's true origin, age, and specification level. Misrepresented engines can lead to compatibility issues and unexpected maintenance costs.
The RD28T NEO engine represents a significant upgrade over the standard version, offering improved power delivery, better fuel efficiency, and reduced emissions. For applications where the initial cost is less critical than long-term operating expenses, the NEO variant typically provides better overall value despite its higher acquisition cost.
How to DIY and Replace RD28T Engine
Replacing an RD28T engine is a complex but manageable DIY project for those with intermediate to advanced mechanical skills. This comprehensive guide outlines the step-by-step process to safely and effectively replace your engine.
Preparation Tip: Before beginning the replacement process, thoroughly photograph and label all connections, hoses, and wiring harnesses. This documentation will prove invaluable during reassembly, especially for components that aren't immediately visible or accessible.
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Safety Precautions
Begin by securing the vehicle on level ground with wheel chocks. Use quality jack stands rated for your vehicle's weight. Disconnect the negative battery terminal to prevent electrical shorts. Wear appropriate safety gear including gloves, eye protection, and steel-toed footwear.
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Tool and Material Preparation
Consult your vehicle's service manual to identify specific tools required. At minimum, you'll need a complete socket set (metric), torque wrench, engine hoist rated for at least 1,000 pounds, engine stand, and a comprehensive RD28T gasket set. Having specialized tools like a fuel line disconnect tool will simplify the process.
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Vehicle Preparation
Remove the hood for unobstructed access. Disconnect and label all electrical connections to the engine. Drain all fluids including coolant, engine oil, and power steering fluid. Remove the radiator, fan shroud, and auxiliary components that might obstruct engine removal.
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Exhaust and Transmission Separation
Disconnect exhaust components at the manifold. For manual transmissions, remove the clutch slave cylinder and bell housing bolts. For automatics, disconnect the torque converter and transmission cooler lines. Support the transmission with a jack before separation.
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Engine Hoist Connection
Attach the engine hoist to the appropriate lifting points using sturdy chains or straps. The RD28T has designated lifting eyes – typically one at the front and one at the rear of the cylinder head. Double-check that all mounting bolts are completely removed before attempting to lift.
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Engine Removal Process
Apply slight tension on the hoist to take weight off the engine mounts. Remove the mount bolts and slowly raise the engine, continually checking for any remaining connections. Extract the engine carefully, maintaining balance to prevent damage to engine or surrounding components.
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New Engine Installation
Transfer any necessary components from the old engine to the new one, including the intake manifold, alternator, and power steering pump. Lower the new engine carefully into position, ensuring proper alignment with transmission input shaft and engine mount brackets.
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Reconnection and Testing
Reconnect all systems in reverse order of disassembly. Refill all fluids to proper levels using manufacturer-specified products. Before starting, crank the engine with spark plugs removed to build oil pressure. After assembly, start the engine and check for leaks, unusual noises, or warning lights.
Critical Warning: Never work under a vehicle supported only by a jack. Always use properly rated jack stands placed at manufacturer-recommended lifting points. Engine replacement involves working with heavy components that can cause serious injury if improperly handled.
Frequently Asked Questions
The RD28T engine performs best with high-quality diesel-specific engine oil. Look for products meeting the SAE 15W-40 or 5W-40 specification with the appropriate API classification (typically CJ-4 or newer). These oils provide excellent thermal stability and wear protection under the high-pressure conditions created by the turbocharger. In colder climates, 5W-40 offers better cold-start protection, while 15W-40 may be preferable in hotter environments.
The RD28T can be adapted to run on biodiesel blends up to B20 (20% biodiesel, 80% petroleum diesel) with minimal modifications. Higher biodiesel concentrations may require fuel system upgrades, including replacing rubber components with biodiesel-compatible materials. The engine's mechanical fuel pump and injection system design make it relatively adaptable to alternative fuels compared to more modern common-rail diesel engines with electronic management systems.
With proper maintenance, the RD28T engine is renowned for its exceptional durability. Many properly maintained examples have surpassed 500,000 kilometers without major internal repairs. The key factors affecting longevity include:
- Regular oil changes with quality diesel-specific oil
- Timely replacement of air and fuel filters
- Adequate cooling system maintenance
- Addressing minor issues before they escalate
- Avoiding excessive idling and proper warm-up procedures
The robust design with relatively low internal stress levels contributes significantly to the engine's reputation for reliability.
Yes, the RD28T engine was factory-paired with both manual and automatic transmissions in various applications. When retrofitting an automatic transmission to an RD28T, it's important to select a model specifically designed for the torque characteristics of this engine. The most common compatible automatic transmissions include the Nissan RE4R03A and the Aisin AW30-40LE series. Proper adapter plates and torque converter selection are essential for successful integration.
The RD28T responds well to several performance modifications:
- Enhanced Airflow: High-flow air filters and larger intake piping can improve turbocharger response
- Turbocharger Upgrades: Larger or more efficient turbochargers can increase power output
- Intercooler Improvements: Larger or more efficient intercoolers reduce intake temperatures and increase power
- Exhaust System Upgrades: Reducing back-pressure through larger exhaust components improves efficiency
- Fuel Delivery Enhancements: Optimized injection pumps and larger injectors can increase power
When modifying the RD28T, it's important to maintain balance between components to ensure reliability is not compromised in pursuit of performance gains.