Nissan TD23 Specifications
| Engine Model: Nissan TD23 |
| Engine Type: 4-cycle inline 4-cylinder OHV 8-valve liquid-cooled diesel |
| Total Displacement: 139.7 cu.in (2.28 L) |
| Rated Engine Power: 75 Hp (56 kW) at 4300 rpm |
| Fuel System Type: Indirect injection |
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The Nissan TD23 is a 2.3-liter, inline-four diesel
engine produced from the mid-1980s through the mid-1990s as part of Nissan’s TD
series. This engine was developed for commercial and light-duty applications
where durability, mechanical simplicity, and resistance to harsh operating
conditions were prioritized over outright power output. The TD23 is a naturally
aspirated diesel utilizing indirect injection (IDI) and a gear-driven valvetrain
- a design that distinguishes it from belt- or chain-driven contemporaries by
eliminating the need for timing component replacement.
The TD23 is constructed entirely from cast iron, with both the cylinder block
and cylinder head manufactured from this material. This all-iron construction
contributes to the engine’s substantial mass but provides exceptional rigidity,
thermal stability, and resistance to wear. The valvetrain employs an overhead
valve (OHV) configuration with two valves per cylinder, actuated by a camshaft
located in the cylinder block and driven directly by the crankshaft through a
set of helical gears.
The mechanical injection system utilizes a Bosch-type distribution pump, a
design chosen for its reliability and serviceability. The TD23 was installed in
Nissan light trucks, vans, and commercial vehicles, where its reputation for
longevity - often exceeding 500,000 km (300,000 mi) with proper maintenance -
made it a favored powerplant for fleet and delivery applications.
The TD23 is a water-cooled, four-stroke, naturally aspirated diesel engine
configured for longitudinal mounting in rear-wheel-drive and four-wheel-drive
commercial vehicles. Its design emphasizes durability, low-end torque, and ease
of service.
Engine Type: Inline-4, 4-cycle, water-cooled, naturally aspirated diesel.
Displacement: 2,289 cc (139.7 cu.in).
Bore and Stroke: 89.0 mm (3.50 in) x 92.0 mm (3.62 in).
Compression Ratio: 22.0:1.
Valvetrain: OHV, 8-valve (2 valves per cylinder) with gear drive.
Fuel System: Indirect injection (IDI) with Bosch-type distribution pump.
Firing Order: 1-3-4-2.
Maximum Power: 56 kW (75 hp) at 4,300 rpm.
Maximum Torque: 151 Nm (111 lb-ft) at 2,200 rpm.
Idle Speed: 650-750 rpm.
Maximum Engine Speed: 4,500 rpm (governor limited).
The cylinder block is constructed from gray cast iron,
a material selected for its exceptional rigidity, vibration-damping properties,
and long-term dimensional stability under the elevated cylinder pressures
generated by diesel combustion. The block features a closed-deck design where
the cylinder bores are fully supported by the water jacket structure at the top
deck surface, providing robust clamping force for the cylinder head gasket and
minimizing bore distortion under thermal and mechanical loads.
Cast-in-place cylinder bores are machined directly into the iron casting. The
block incorporates five main bearing webs with two-bolt main bearing caps. The
crankshaft is supported by five bearings and is constructed from forged steel to
withstand the high cylinder pressures of diesel operation. A stamped steel oil
pan is sealed to the lower crankcase, providing the oil reservoir. The block
design incorporates the camshaft gallery and the gear-driven timing system
within the front structure, with an access cover providing serviceability.
Block Material: Gray cast iron.
Bore Diameter (finished): 89.0 mm (3.50 in).
Main Bearing Caps: Cast iron, two-bolt design.
Cylinder Bore Deformation Limit: 0.05 mm (0.0020 in).
The cylinder head is manufactured from gray cast iron,
matching the block material to ensure uniform thermal expansion across the
cylinder head gasket interface. This all-iron construction provides exceptional
durability and resistance to thermal cycling, though it contributes to the
engine’s substantial overall mass. The head incorporates a pre-chamber indirect
injection system, with each cylinder equipped with a pre-chamber insert and a
glow plug.
The OHV valvetrain actuates eight valves - two valves per cylinder - through a
system of pushrods and rocker arms. The camshaft is located in the cylinder
block and is driven directly by the crankshaft through a set of helical gears.
The gear-driven valvetrain eliminates the need for timing belt or chain
replacement, representing a significant maintenance advantage.
Valve clearance is adjusted manually via threaded adjusters on the rocker arms.
The pre-chamber combustion system, integrated into the cylinder head, creates
turbulence in the air-fuel mixture before combustion, allowing for smooth
operation across a wide range of engine speeds. The engine is of interference
design; however, the gear-driven valvetrain eliminates the risk of timing
component failure common to belt- or chain-driven engines.
Head Material: Gray cast iron.
Valve Configuration: OHV, 2 valves per cylinder with pushrods and rocker arms.
Valve Diameter (Intake): 42.0 mm (1.65 in).
Valve Diameter (Exhaust): 38.0 mm (1.50 in).
Valve Stem Diameter: 8.0 mm (0.31 in).
Valve Seat Angle: 45 degrees.
The TD23 employs an indirect injection system utilizing
a Bosch-type mechanical distribution pump. The system uses a pre-chamber located
in the cylinder head, into which fuel is injected before combustion propagates
into the main combustion chamber. This design reduces combustion noise and
allows for smooth operation at lower engine speeds, though it imposes a penalty
on specific fuel consumption compared to direct injection systems.
The Bosch-type distribution pump is mechanically governed, with a centrifugal
governor controlling fuel delivery based on engine speed and load. The pump
delivers fuel to four individual injection lines that feed nozzle holders
mounted in the pre-chambers. Injection timing is adjusted by rotating the
injection pump relative to the drive gear. A manual fuel shut-off cable or
electric solenoid provides engine shutdown. The mechanical injection system
offers high tolerance for variable fuel quality and eliminates reliance on
electronic sensors for basic engine operation.
Injection Type: Indirect injection (pre-chamber).
Injection Pump: Bosch-type mechanical distribution pump with centrifugal
governor.
Injection Pressure (nozzle opening): 11.8-12.8 MPa (1,710-1,860 psi).
Injection Timing: 15-17° before top dead center (dynamic, engine running).
Fuel Requirement: Diesel fuel meeting applicable standards (cetane number 45
minimum).
The lubrication system is a fully pressurized, wet-sump
design utilizing a gear-type oil pump mounted to the front of the crankshaft.
The oil pump draws lubricant from the stamped steel oil pan through a mesh
strainer and circulates it through a full-flow, replaceable oil filter before
entering the main oil gallery. From the gallery, pressurized oil is distributed
to the crankshaft main bearings, connecting rod bearings, camshaft bearings,
rocker arm assemblies, pushrods, and timing gears.
A pressure relief valve integrated into the oil pump maintains system pressure
within operational limits to prevent over-pressurization during cold starts. The
lubrication system is designed for extended oil change intervals under normal
operating conditions when using approved diesel-grade lubricants.
Oil Type: SAE 15W-40, 20W-50, or single-grade SAE 30 (API CD, CE, or CF).
Oil Capacity (with filter): 5.5-6.0 liters (5.8-6.3 US qt).
Oil Pressure (at 3,000 rpm): 294-392 kPa (42.6-56.9 psi).
Oil Pump Type: Gear-type, crankshaft-driven.
Oil Filter Type: Spin-on, full-flow.
The cooling system is a pressurized, liquid-cooled
design employing a cross-flow copper-brass or aluminum radiator with an
engine-driven cooling fan and viscous clutch. A centrifugal-type water pump,
driven by the accessory belt, circulates coolant through the engine block,
cylinder head, and heater core. A wax-pellet thermostat regulates coolant flow
to maintain optimal operating temperature, with a bypass circuit that allows the
engine to warm rapidly by circulating coolant only within the engine until the
thermostat opens.
The cooling system is sized to manage the thermal load of the diesel engine
under sustained load conditions, such as commercial delivery or towing
applications. The all-iron construction requires consistent operating
temperature to maintain proper piston-to-bore clearances and cylinder head
gasket sealing.
Coolant Type: Ethylene-glycol based antifreeze with corrosion inhibitors.
Coolant Capacity: 7.5-8.5 liters (7.9-9.0 US qt) (variant dependent).
Thermostat Opening Temperature: 76-82 °C (169-180 °F).
Thermostat Full-Open Temperature: 90 °C (194 °F).
Radiator Cap Pressure: 70-100 kPa (10.2-14.5 psi).
Water Pump Type: Centrifugal, accessory belt-driven.
Timing Drive: The camshaft and injection pump are
driven by a set of helical gears from the crankshaft. The gear train is housed
within the front timing cover, with the crankshaft gear driving the camshaft
gear and an additional gear driving the injection pump. The gear-driven system
eliminates scheduled timing component replacement and provides exceptional
durability.
Intake System: Cast iron intake manifold with a single inlet from the air
cleaner housing. The intake system incorporates an air cleaner housing with a
dry-type paper filter element. An air pre-heater system on some variants routes
intake air across the exhaust manifold to improve cold-start performance.
Exhaust System: Cast iron exhaust manifold with individual runners collecting
into a single downpipe. The exhaust system is constructed from steel with a
single muffler.
Overall Length: 780 mm (30.7 in).
Overall Width: 630 mm (24.8 in).
Overall Height: 780 mm (30.7 in).
Dry Weight (complete engine): 220-235 kg (485-518 lb).
Oil Change Interval: 7,500 km (4,700 mi) under normal
driving conditions.
Oil Change Interval: 5,000 km (3,100 mi) under severe conditions.
Oil Filter Change: At every oil change.
Timing Gear Inspection: Inspect gear noise at each service interval.
Engine Coolant Replacement: 30,000 km (18,000 mi) or 2 years.
Glow Plug Inspection: Check at each major service; replace as required.
Drive Belt (Accessory) Inspection: Every 10,000 km (6,000 mi) for tension,
cracking, and glazing.
Air Filter Replacement: 15,000 km (9,000 mi) or as indicated by inspection.
Fuel Filter Replacement: 15,000 km (9,000 mi).
Valve Clearance Adjustment: Inspect and adjust every 10,000-15,000 km
(6,000-9,000 mi).
Valve Clearance Intake and exhaust: 0.30-0.35 mm (0.0118-0.0138 in) cold.
Idle Speed Adjustment: 650-750 rpm; adjust via idle speed screw on injection
pump.
Injection Timing Adjustment: Inspect as required; timing marks on injection pump
drive gear and front cover.
Cylinder Head Bolts (M12 x 1.5), 1st pass: 40 Nm (30
lb-ft).
Cylinder Head Bolts (M12 x 1.5), 2nd pass: 80 Nm (59 lb-ft).
Cylinder Head Bolts (M12 x 1.5), final pass: 130 Nm (96 lb-ft).
Main Bearing Cap Bolts (M12 x 1.5): 90-100 Nm (66-74 lb-ft).
Connecting Rod Cap Bolts (M10 x 1.25): 50-55 Nm (37-41 lb-ft).
Rocker Arm Shaft Bolts (M8 x 1.25): 18-22 Nm (13-16 lb-ft).
Intake Manifold Bolts (M8 x 1.25): 18-22 Nm (13-16 lb-ft).
Exhaust Manifold Nuts (M8 x 1.25): 18-22 Nm (13-16 lb-ft).
Glow Plugs: 20-25 Nm (15-18 lb-ft).
Oil Pan Bolts (M6 x 1.0): 8-10 Nm (71-89 lb-in).
Water Pump Bolts (M8 x 1.25): 18-22 Nm (13-16 lb-ft).
Crankshaft Pulley Bolt (M18 x 1.5): 250-280 Nm (184-207 lb-ft).
Flywheel / Drive Plate Bolts (M10 x 1.25): 70-75 Nm (52-55 lb-ft).
Injection Pump Drive Gear Nut (M12 x 1.5): 45-50 Nm (33-37 lb-ft).
The Nissan TD23 engine was utilized across a range of
Nissan light commercial vehicles, vans, and pickup trucks throughout its
production period from the mid-1980s to the mid-1990s.
Nissan Atlas (F22 / F23): 1986-1995 model years.
Nissan Caravan / Urvan (E24): 1986-1995 model years.
Nissan Datsun Truck / Navara (D21): 1987-1992 model years.
Nissan Homy (E24): 1986-1995 model years.
Nissan Civilian (W40): Select bus and commercial variants with TD23 engine.
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