Komatsuengine(no series)

Komatsu N14-(S/N 1-UP)

Maintenance schedule, common problems & OEM parts breakdown

The Komatsu N14-(S/N 1-Up) listing covers the Cummins-built N14, a 14.0 L (855 cu in) turbocharged and aftercooled inline-six diesel with a 140 mm x 152 mm (5.5 in x 6.0 in) bore and stroke, offered with mechanical CELECT or later CELECT Plus electronic fuel control. Komatsu specified this Cummins engine, rather than its own SA6D140E-series unit, as the powerplant for select PC600-6 series crawler excavators (including PC600-6, PC600-6KJ, PC600-6-W1, and PC600LC-6 variants) rated near 385 hp gross, and for WA500-series wheel loaders: the WA500-3L rated near 335 hp gross (315 hp net) and the earlier WA500-1LE rated near 291 hp. Host operating weights vary by model and configuration, running roughly 26 to 30 tonnes (57,000-65,000 lb) on the WA500 loaders and in the 54-60 tonne class on the PC600-6 excavator line. These host platforms were built chiefly from the early 1990s (WA500-1 series) through the early-to-mid 2000s (PC600-6 and WA500-3 series), with the N14 serving as the high-power or export alternative alongside Komatsu's own engine on the same chassis.

Across its Komatsu fitments the N14 progressed from mechanical CELECT metering to CELECT Plus electronic control, adding closer fuel and torque management and diagnostic capability while keeping the same 14 L mechanical architecture, wet-liner block, turbocharger, and aftercooler layout throughout the range. Because Komatsu sourced this engine rather than building it in-house, N14-powered PC600-6 and WA500-3L/WA500-1LE units sit in a distinct service niche: they draw on the wider Cummins N14 support base built up over decades of on-highway truck use, instead of Komatsu's own engine parts chain. That makes surviving host machines and sound used N14 cores valuable to owners who prefer Cummins-familiar service over OEM-only support, and it keeps demand steady for good used and rebuildable engines even as Komatsu's own SA6D140E-equipped siblings dominate the surviving population. It is also why identification matters: mixing parts or specs between this Cummins listing and the outwardly similar Komatsu-engine PC600LC-6 and WA500 units is a common but avoidable error in the used market.

Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.

Komatsu N14-(S/N 1-UP) specifications

Engine

Model	N14-(S/N 1-UP) — Cummins-built engine fitted by Komatsu to select PC600-6 series excavators (PC600-6, PC600-6KJ, PC600-6-W1, PC600LC-6 family) and L-suffix WA500 wheel loaders (WA500-1LE, WA500-3L), in place of Komatsu's own SA6D140E-series engine
Configuration	Water-cooled, 4-cycle, in-line 6-cylinder, direct injection, turbocharged with aftercooler; offered with mechanical CELECT or later CELECT Plus electronic fuel control depending on production series
Cylinders	6
Bore x Stroke	140 mm x 152 mm (5.5 in x 6.0 in)
Displacement	14.0 L (855 cu in)
Gross power	Approx. 250 kW (335 hp) — figure documented for the WA500-3L application; varies by rating/series
Net/flywheel power	Approx. 217-235 kW (291-315 hp) — lower rating (291 hp) documented for WA500-1LE, higher (315 hp) for WA500-3L; varies by configuration/series
Emissions tier	Not documented — pre-emissions-certification generation; certification tier varies by CELECT vs CELECT Plus fuel-control series and is not listed in available spec sheets

Weights

Note on scope	No standalone bare-engine dry weight is published in available dealer/spec sources for this unit — verify with your dealer or the Komatsu shop manual for this engine
Host machine operating weight (WA500-3L)	Approx. 29,470 kg (64,970 lb), varies by bucket and counterweight configuration

Dimensions

Note on scope	Figures below are for the WA500-3L host wheel loader chassis (bare-engine block dimensions are not published)
Overall length, bucket on ground	9.2 m (30.2 ft)
Overall width, over tires	3.2 m (10.5 ft)
Overall height, to cab top	3.9 m (12.7 ft)
Wheelbase	3.6 m (11.8 ft)
Ground clearance	0.46 m (1.5 ft)

Performance

Note on scope	Travel-speed and cycle-time figures are host-machine (WA500-3L) performance, not standalone engine ratings
Max forward travel speed	Approx. 33 km/h (20.5 mph)
Max reverse travel speed	Approx. 36 km/h (22.4 mph)
Turning radius	6.5 m (21.4 ft)
Bucket raise time	6.4 sec
Bucket dump time	1.7 sec
Bucket lower time	3.5 sec

Service capacities (summary)

Fuel tank	Approx. 460 L (121.5 gal) — host machine capacity
Hydraulic system	Approx. 175 L (46.2 gal) — host machine capacity
Engine oil	Approx. 37 L (9.8 gal)
Cooling system	Approx. 99 L (26.2 gal)

Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.

N14-(S/N 1-UP) fluids & capacities

System	Capacity	Recommended fluid
Engine crankcase (with filter)	approx. 30-42 L (8-11 US gal); figure varies by oil pan configuration (standard front-sump vs. high-capacity rear-sump pan)	SAE 15W-40 heavy-duty diesel engine oil, API CG-4/CH-4 or later, meeting the Cummins engine oil spec for this engine generation. Below about -15°C (5°F) use SAE 10W-30 rated for cold start; SAE 5W-40 synthetic is called out for extreme cold below roughly -18°C (0°F).
Cooling system (engine jacket water, exclusive of external radiator/system plumbing which is chassis-dependent)	approx. 19-20 L (20-21 US qt / about 5-5.5 US gal)	Fully-formulated heavy-duty ethylene-glycol coolant/antifreeze with supplemental coolant additive (SCA), or extended-life OAT coolant. Maintain SCA/additive concentration per the coolant test-strip schedule; do not mix OAT and conventional coolant chemistries.
Grease (chassis/accessory-drive points)	not documented for this standalone engine listing	not documented for this standalone engine listing — verify with your dealer

Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.

Komatsu N14-(S/N 1-UP) maintenance schedule

Service interval	Tasks
Every 50 h	Check engine oil level before start-up; top off to the full mark if low. Check coolant level at the surge tank or sight glass; add the correct coolant/SCA mix if low. Drain water and sediment from the primary fuel filter/water separator. Walk around and check for fuel, oil, and coolant leaks at the engine, turbocharger, and aftercooler connections. Check the air cleaner restriction indicator; service the element if it shows red. Listen for unusual turbocharger whine or induction noise and check for loose intake clamps.
Every 250 h	Change engine oil and the full-flow oil filter, or per current oil-analysis result. Replace the fuel filter/water separator element. Check fan, alternator, and water pump drive belt tension and condition; adjust or replace as needed. Inspect the crankcase breather for restriction and clean it. Check engine mounting bolts and isolators for looseness or cracking.
Every 500 h	Pull an oil sample and a coolant sample for laboratory analysis. Test coolant SCA/DCA concentration and freeze protection; add supplemental coolant additive if low. Inspect turbocharger shaft end play and boost/oil supply lines for leaks. Check the engine speed governor and throttle linkage for free movement and correct adjustment. Inspect the exhaust manifold, turbocharger mounting hardware, and exhaust piping for cracks or leaks.
Every 1,000 h	Replace the air cleaner primary element regardless of restriction-gauge reading. Inspect and adjust the cooling fan belt tensioner and idler pulleys. Inspect the charge-air cooler (aftercooler) core and hoses for leaks, cracks, or fouling. Run a full coolant panel (SCA/DCA, pH, glycol percentage) rather than a spot check. Inspect the vibration damper for rubber bond separation or visible wobble.
Every 2,000 h	Check and adjust valve lash and fuel injector settings to the factory clearance specification. Inspect and, if needed, recondition the turbocharger cartridge for shaft play and housing cracks. Inspect the CELECT/CELECT Plus wiring harness, sensors, and ECM connectors for corrosion or chafing. Replace the coolant filter/conditioner element, if fitted, and recheck additive concentration. Torque-check accessible cylinder head fasteners and intake/exhaust manifold hardware.
Every 4,000 h	Drain, flush, and refill the complete cooling system with fresh coolant and a full SCA/DCA charge. Re-inspect wet cylinder liners for cavitation pitting during any head or liner-adjacent work. Replace the vibration damper if inspection at the prior interval showed any separation. Pressure-test the aftercooler core and replace deteriorated intake/charge-air hoses and clamps. Evaluate blow-by, oil consumption, and compression trends to plan an inframe overhaul before failure occurs.
Every 8,000 h	Perform an inframe overhaul when oil consumption, blow-by, or compression readings exceed factory limits: renew liners, pistons, rings, and rod/main bearing sets together. Recondition or replace the cylinder head, including valve guides, seats, and injector cups, as wear dictates. Overhaul or replace the turbocharger rather than continuing to service individual components. Replace the vibration damper and accessory drive components as a preventive set during teardown. Verify governor, CELECT/CELECT Plus calibration, and injector timing are restored to factory spec before returning the engine to service.

Servicing the N14-(S/N 1-UP) beyond the schedule

Predictive Maintenance & Fluid Analysis

Run scheduled oil and coolant sampling on this N14 rather than relying on hours alone. Track total base number and soot loading in the 14 L sump to catch injector or ring wear before it shows as smoke or oil consumption on the PC600-6 or WA500 host. Monitor coolant SCA/DCA additive level and pH to protect wet cylinder liners from cavitation pitting, a known N14 failure mode. Watch turbocharger boost and exhaust temperature trends for early bearing or aftercooler fouling signs.

Corrective & Common Repairs

Typical N14 repairs on these Komatsu hosts center on the CELECT/CELECT Plus injector and fuel system: sticking or leaking injectors, worn injector adjusting screws, and fuel pump timing drift are the most common driveability complaints. Turbocharger shaft play and cracked exhaust manifolds follow from heat cycling in excavator and loader duty. Address wet-liner cavitation leaks and head gasket seepage promptly, since coolant intrusion into the 14 L block is the leading cause of unplanned N14 teardown on PC600-6 and WA500 units.

Overhaul & Rebuild Points

When an inframe overhaul is due, renew the wet liners, pistons, rings, and rod/main bearing sets as a set rather than mixing new and used components in the 14 L block. Recheck valve lash and injector adjustment to factory clearance after any head or valvetrain work. Inspect the vibration damper for rubber-to-hub separation before reinstalling, and pressure-test the aftercooler core. On PC600-6 and WA500-3L/1LE applications, verify the turbocharger match and boost lines are restored to original routing.

Seasonal & Environment Servicing

In cold climates, switch to the correct winter-grade fuel and use a properly maintained coolant SCA/DCA charge to protect the N14's wet liners from freeze and cavitation damage, and confirm the block heater and starting aid on the PC600-6 or WA500 host are functional before cold starts. In hot, dusty excavator and loader environments, shorten air cleaner and aftercooler-core inspection intervals to prevent intake restriction and derated power, and check coolant fan drive and radiator/aftercooler fin packs for packed debris that raises operating temperature.

N14-(S/N 1-UP) common service parts

Part number	Part	Notes
CU3918334	Oil Filter	Lubrication service	Check fitment →
CU3401544	Element,Engine Oil	Lubrication service	Check fitment →
CU3844234	Element	Scheduled service item	Check fitment →

Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.

N14-(S/N 1-UP) fault codes & troubleshooting

Code	Meaning	Likely cause	What to do
111	ECM microprocessor fault (internal control module failure)	Internal ECM hardware/processor fault, often paired with code 343	Cycle key power and recheck; if code returns immediately, replace the ECM
115 / 121	Engine Position Sensor (crank/cam timing reference) circuit fault	Damaged magnetic pickup sensor, wide sensor air gap, or open/shorted wiring at the timing gear cover	Inspect sensor mounting and air gap, check wiring continuity, test sensor resistance and replace if out of spec
122 / 123	Intake Manifold (boost) Pressure Sensor circuit fault	Failed sensor, disconnected or pinched sense hose, or wiring short to ground/battery	Check sensor connector and hose routing, verify sensor supply voltage, replace sensor if faulty
143	Low oil pressure engine protection (shutdown or derate)	Actual low oil pressure, plugged oil filter/pickup, or a failed oil pressure sensor	Verify oil level and actual pressure with a mechanical gauge before condemning the sensor; replace sensor only if pressure checks normal
151	High coolant temperature engine protection (shutdown or derate)	Low coolant, plugged radiator/core, stuck thermostat, or faulty coolant temp sensor	Check coolant level and actual temperature with a gauge, inspect cooling system airflow before replacing the sensor
234	Engine overspeed event	Sudden load loss, downhill overrun, engine brake malfunction, or sticking throttle linkage	Review event/snapshot data for the overspeed cause, inspect governor and throttle linkage, check engine brake operation
235	Low coolant level engine protection	Low coolant, air pocket in the cooling system, or failed coolant level probe/sensor	Check coolant level, bleed the cooling system, inspect the level sensor and its connector
343	Fault Processing Computer (FPC) chip fault, internal ECM diagnostic processor error	Internal ECM component failure, commonly appears together with code 111	Cycle key power; if the fault is active and repeats, replace the ECM
434	Unswitched battery supply circuit low voltage to the ECM	Weak or discharged battery, corroded/loose ECM power connection, blown fuse, or poor ground	Check battery voltage, inspect and clean ECM power and ground connections, verify fuse and wiring integrity
254	Fuel shutoff solenoid supply circuit fault	Open or shorted wiring to the fuel shutoff solenoid, blown fuse, or failed relay	Inspect solenoid wiring and connector, test supply voltage at the solenoid, replace the solenoid if it fails to actuate

Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.

All N14-(S/N 1-UP) assemblies by section

Every catalogued assembly group for the Komatsu N14-(S/N 1-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Engine

Komatsu : N14-(S/N 1-Up) : Engine : Accessory Drive Pulley

CU***33	Screw	6
CU***20	Pulley	1

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Komatsu : N14-(S/N 1-Up) : Engine : Aftercooler Water Plumbing

CU***56	Connection	1
CU***02	Connection	1
CU***57	Connection	1
CU***50	Plug	3

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Komatsu : N14-(S/N 1-Up) : Engine : Agency Approval

CU***14	Plate? Data	1
CU***08	Screw	3

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Komatsu : N14-(S/N 1-Up) : Engine : Air Fuel Control Assembly

CU***39	Elbow,(Not Shown)	1
CU***SS	Hose	1

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Komatsu : N14-(S/N 1-Up) : Engine : Alternator

CU***18

Alternator

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Komatsu : N14-(S/N 1-Up) : Engine : Alternator Mounting

CU***60	Washer	1
CU***29	Bolt	1
CU***10	Washer	3
CU***06	Screw	1

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Komatsu : N14-(S/N 1-Up) : Engine : Cam Follower

CU***-A	Screw	14
CU***41	Plug	1
CU***37	Roller	1
CU***12	Lever	2

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Komatsu : N14-(S/N 1-Up) : Engine : Camshaft

CU***33	Key	1
CU***33	Bearing	1
CU***93	Plug	1
CU***02	Camshaft	1

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Komatsu : N14-(S/N 1-Up) : Engine : Celect Fuel Pump

CU***74	Cover Ass'Y	1
CU***23	Spring Pack Ass'Y	1
CU***43	Gear Ass'Y	1
CU***56	Fuel Pump Ass'Y	1

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Komatsu : N14-(S/N 1-Up) : Engine : Coolant Heater Starting Aid

CU***70

Heater

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Komatsu : N14-(S/N 1-Up) : Engine : Corrosion Resistor

CU***12	Hose	1
CU***06	Resistor	1
CU***98	Bracket	1
CU***01	Valve	2

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Komatsu : N14-(S/N 1-Up) : Engine : Crankcase Breather

CU***96	Clamp	2
CU***10	Brace	1
CU***34	Tube	1
CU***02	Washer	2

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Komatsu : N14-(S/N 1-Up) : Engine : Crankshaft

CU***74	Metal	3
CU***45	Dowel	7
CU***04	Metal	1
CU***92	Metal	3

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Komatsu : N14-(S/N 1-Up) : Engine : Crankshaft Pulley

CU***54	Bolt	6
CU***23	Pulley	1
CU***16	Washer	6
CU***23	Damper	1

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Komatsu : N14-(S/N 1-Up) : Engine : Cylinder Block

CU***51	Bushing	1
CU***36	Plug	3
CU***75	Pin	1
CU***47	Ring	0

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Komatsu : N14-(S/N 1-Up) : Engine : Cylinder Head

CU***15	Insert	4
CU***59	O-Ring	2
CU***60	Spring	8
CU***12	Guide	8

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Komatsu : N14-(S/N 1-Up) : Engine : Cylinder Liner Kit

CU***90	Seal	1
CU***26	Kit	6
CU***74	Seal	2

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Komatsu : N14-(S/N 1-Up) : Engine : Electric Starting Accessories

CU***38

Starting Motor Ass'Y

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Komatsu : N14-(S/N 1-Up) : Engine : Engine Fan

CU***57

Fan

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Komatsu : N14-(S/N 1-Up) : Engine : Engine Oil Cooler

CU***38	Thermostat	1
CU***00	Screw	1
CU***76	Plug	1
CU***36	Plug	5

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Komatsu : N14-(S/N 1-Up) : Engine : Engine Piston

CU***98	Ring	1
CU***49	Bearing	12
CU***97	Ring	1
CU***90	Seal	1

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Komatsu : N14-(S/N 1-Up) : Engine : Exhaust Outlet Connection

CU***17

Clamp

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Komatsu : N14-(S/N 1-Up) : Engine : Fan Drive

CU***18	Pulley	1
CU***21	Hub	1
CU***10	Washer	4
CU***25	Bracket	1

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Komatsu : N14-(S/N 1-Up) : Engine : Fan Spacer And Pilot

CU***28

Spacer

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Komatsu : N14-(S/N 1-Up) : Engine : Flyheel Housing

CU***53	Screw	9
CU***94	Screw	8
CU***08	Pin	2
CU***84	Housing	1

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Komatsu : N14-(S/N 1-Up) : Engine : Flywheel Housing Plumbing

CU***79

Plug

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Komatsu : N14-(S/N 1-Up) : Engine : Front Engine Support

CU***29	Support	1
CU***64	Screw	2
CU***89	Screw	6

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Komatsu : N14-(S/N 1-Up) : Engine : Front Gear Cover

CU***53	Dowel	1
CU***36	Plug	1
CU***58	Cover	1
CU***18	Gasket	1

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Komatsu : N14-(S/N 1-Up) : Engine : Fuel Filter

CU***SS	Hose	1
CU***13	Head	1
CU***59	Elbow	2
CU***17	O-Ring	2

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Komatsu : N14-(S/N 1-Up) : Engine : Fuel Pump Drive

CU***87	Housing	1
CU***00	Spider	1
CU***64	Washer	1
CU***25	Gasket	1

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Komatsu : N14-(S/N 1-Up) : Engine : Fuel Pump Mounting

CU***83	Washer	2
CU***24	Washer	2
CU***74	Nut,(Not Shown)	2
CU***99	Screw	2

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Komatsu : N14-(S/N 1-Up) : Engine : Fuel Shutoff Valve

CU***38	Knob	1
CU***68	Spring	1
CU***57	Disk	1
CU***58	Plug	1

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Komatsu : N14-(S/N 1-Up) : Engine : Fuel System Primer Plumbing

CU***68	Spacer	1
CU***SS	Hose	1
CU***09	Washer	1
CU***10	Brace	1

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Komatsu : N14-(S/N 1-Up) : Engine : Full Flow Oil Filter

CU***42	Elbow	2
CU***78	Hose	1
CU***89	Clip	4
CU***66	O-Ring	2

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Komatsu : N14-(S/N 1-Up) : Engine : Hydraulic Variable Timing Tappet

CU***52	Spring	1
CU***83	Tappet	1
CU***88	Ring	1
CU***33	Guide	1

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Komatsu : N14-(S/N 1-Up) : Engine : Injector

CU***18	Retainer	1
CU***34	Adapter	1
CU***38	Retainer	1
CU***31	Slinger	1

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Komatsu : N14-(S/N 1-Up) : Engine : Lifting Bracket

CU***26	Screw	1
CU***33	Screw	5
CU***57	Bracket	1
CU***29	Bracket	1

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Komatsu : N14-(S/N 1-Up) : Engine : Lube Oil Pump

CU***61	Screw	2
CU***36	Plug	1
CU***89	Screw	1
CU***54	Washer	1

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Komatsu : N14-(S/N 1-Up) : Engine : Manual Control

CU***77	Lever	1
CU***51	Nut	1
CU***04	Washer	2
CU***-B	Bolt	1

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Komatsu : N14-(S/N 1-Up) : Engine : Oil Control Valve

CU***14	O-Ring	1
CU***37	Bolt	4
CU***99	Bolt	3
CU***66	O-Ring	1

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Komatsu : N14-(S/N 1-Up) : Engine : Oil Control Valve Mounting Plumbing

CU***27	Valve	1
CU***SS	Hose	1
CU***02	Washer	2
CU***26	Washer	2

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Komatsu : N14-(S/N 1-Up) : Engine : Oil Cooler Water Plumbing

CU***60	Gasket	0
CU***42	Washer	1
CU***68	Plug,(Not Shown)	2
CU***95	Bolt	4

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Komatsu : N14-(S/N 1-Up) : Engine : Oil Level Gauge

CU***02	Washer	0
CU***12	Bolt	0
CU***21	Nut	0
CU***23	Nut,(Not Shown)	0

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Komatsu : N14-(S/N 1-Up) : Engine : Oil Level Sensor

CU***97

Sensor

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Komatsu : N14-(S/N 1-Up) : Engine : Oil Manifold

CU***52	Clip	1
CU***37	Plug	1
CU***66	O-Ring	1
CU***65	Plug	1

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Komatsu : N14-(S/N 1-Up) : Engine : Oil Pan

CU***69	Plug	1
CU***51	Gasket	1
CU***24	Bolt	2
CU***30	Retainer	1

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Komatsu : N14-(S/N 1-Up) : Engine : Oil Pressure Switch

CU***67

Switch

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Komatsu : N14-(S/N 1-Up) : Engine : Piston Cooling Nozzle

CU***54	Bolt	6
CU***27	Seal	6

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Komatsu : N14-(S/N 1-Up) : Engine : Rear Clutch

CU***69	Bushing	1
CU***61	Washer	6
CU***51	Gear	1
CU***55	Flywheel	1

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Komatsu : N14-(S/N 1-Up) : Engine : Ref Compressor Mounting

CU***86	Plug	2
CU***28	O-Ring	1
CU***18	Plug	1
CU***26	Gasket	1

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Komatsu : N14-(S/N 1-Up) : Engine : Remote Oil Drain

CU***20	Valve	1
CU***46	Gasket	1

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Komatsu : N14-(S/N 1-Up) : Engine : Rocker Lever

CU***99	Rod	6
CU***50	Plug	3
CU***55	Pin	6
CU***02	Washer	3

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Komatsu : N14-(S/N 1-Up) : Engine : Starting Motor Mounting

CU***45	Spacer	1
CU***81	Screw	3
CU***03	Washer,Spring	3

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Komatsu : N14-(S/N 1-Up) : Engine : Temperature Sensor

CU***29

Sensor

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Komatsu : N14-(S/N 1-Up) : Engine : Thermostat

CU***66	Plug	1
CU***33	Screw	3
CU***95	Gasket	1
CU***-A	Seal	2

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Komatsu : N14-(S/N 1-Up) : Engine : Turbocharger

CU***63	Screw	4
CU***40	Collar	1
CU***18	Plate	1
CU***75	Shaft	1

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Komatsu : N14-(S/N 1-Up) : Engine : Turbocharger Arrangement

CU***44	Core	1
CU***36	Plug	3
CU***66	Plug	1
CU***48	Seal	1

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Komatsu : N14-(S/N 1-Up) : Engine : Turbocharger Plumbing

CU***26	Washer	2
CU***21	Nut	1
CU***35	Elbow	2
CU***15	Bolt	1

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Komatsu : N14-(S/N 1-Up) : Engine : Valve Cover

CU***01	Seal	1
CU***11	Gasket	3
CU***24	Cover	1
CU***10	Bolt	30

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Komatsu : N14-(S/N 1-Up) : Engine : Viscosity Sensor Kit

CU***34	Hose	1
CU***63	Sensor	1
CU***35	Bracket	1
CU***12	Tee	1

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Komatsu : N14-(S/N 1-Up) : Engine : Water Header Cover

CU***04	Bolt	6
CU***98	Gasket	1
CU***19	Cover	1

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Komatsu : N14-(S/N 1-Up) : Engine : Water Pump

CU***04	Cover	1
CU***98	Seal	1
CU***82	Washer	1
CU***01	Nut	1

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N14-(S/N 1-UP) serial number reference

The N14 is a Cummins-built engine option fitted to select Komatsu PC600-6 excavators and WA500 wheel loaders, not a Komatsu-numbered engine. Its data tag sits on the fuel-pump side of the rocker-lever housing, with the stamped block number as a backup if the tag is gone; the number itself is a plain numeric sequence with no Komatsu-style alpha prefix. The host machine's own PIN plate, riveted to the frame, carries the letter ahead of the equipment serial (none for PC600-6, A for WA500) that identifies the equipment configuration, not the engine itself.

Prefix	Identifies	Notes
10001-Up (no letter prefix)	PC600-6KJ / PC600-6-W1 and PC600LC-6 / PC600LC-6-KJ / PC600LC-6-W1 hydraulic excavator	KJ is the Japan-market chassis code, W1 the worldwide/export chassis code. Both draw the N14 from engine S/N 1-Up. Large hydraulic excavator class, turbocharged inline-6, mechanically injected. This is the equipment/engine pairing matching this exact S/N 1-Up engine range. Do not extend this to PC650-6/PC650-7, which use a different Komatsu 6D140-family engine, not the N14.
A70001-Up	WA500-3L wheel loader	L suffix marks a special-spec WA500-3 build fitted with the Cummins N14 in place of the standard WA500-3's own Komatsu SA6D140E-3 engine. Turbocharged and aftercooled inline-6, roughly 250 kW (335 hp) gross / 235 kW (315 hp) net. Engine serial range not broken out separately from the equipment range in the source cross-reference.
A61001-Up	WA500-1LE wheel loader	LE suffix marks a low-emission/late-production WA500-1 build fitted with the Cummins N14, rated around 217 kW (291 hp), versus the standard WA500-1's Cummins NTA855-C. Engine serial range not documented separately for this configuration - confirm exact engine S/N break with your dealer.

Frequently asked questions

What engine powers the Komatsu N14-(S/N 1-Up) listing?

It is the Cummins-built N14 itself: a 14.0 L (855 cu in) turbocharged, aftercooled inline-six diesel with CELECT or CELECT Plus electronic fuel control, factory-fitted by Komatsu to select PC600-6 series excavators and WA500-3L/WA500-1LE wheel loaders in place of Komatsu's own SA6D140E engine.

What is the operating weight for this listing?

This listing covers the bare N14 engine, not a complete machine, so a standalone engine weight is not published. Host operating weight varies by model: WA500-3L/WA500-1LE wheel loaders run roughly 26-30 tonnes (57,000-65,000 lb), and PC600-6 series excavators run in the 54-60 tonne class, depending on configuration.

What replaced the N14 in later Komatsu machines?

Later PC600 and WA500 generations moved to Komatsu's own SA6D140E-series engines, and eventually emissions-updated SAA6D140E variants, built in-house. This ended Komatsu's use of the Cummins N14 as an alternate powerplant on these platforms.

What N14-(S/N 1-UP) owners discuss

How dependable is this N14 once it's out of a truck and living inside a Komatsu excavator or loader?

About as dependable as its trucking reputation suggests. Owners running these in PC600-6-class excavators and WA500-class loaders say the bottom end (block, crank, rods) rarely quits on its own — engines with very high hours are common when maintenance was kept up. When something goes wrong it's almost always an accessory: an injector, a wiring connector, or the ECM circuit, not the core mechanical engine.

What's the most common driveability complaint with the CELECT/CELECT Plus fuel system?

Rough idle, a miss under load, or white smoke on acceleration that traces back to one weak injector. Owners often replace just the bad one to save money, then are back in the shop again a few months later when a neighboring injector goes. Techs who work on these a lot recommend doing the full set together once the first one fails rather than chasing them one at a time.

We get intermittent no-start and random shutdowns that look like an ECM fault — is it really the module?

Often not. A large share of what looks like an ECM failure — hard hot-starts, random shutdowns, no communication with a diagnostic reader — comes down to corroded ECM power and ground connections: the fuse links off the battery positive and the ground straps to the block or frame. Cleaning and re-terminating those first resolves a lot of alleged ECM complaints without buying a module. Have your dealer verify ECM supply voltage and grounds before condemning the module.

Fuel pressure keeps dropping and cranking takes forever — what are people finding?

A recurring cause is wear in the fuel pump drive coupling inside the front gear train, not the pump itself. As it wears, pressure at the rail gets weak and inconsistent, cranking gets longer (especially on a hot restart), and power fades under load before pressure ever fully collapses. Catching worn pump spines early keeps the problem from cascading into the front gear case.

On a higher-hour machine we're seeing smoke out the crankcase breather and stack under load — is an oil change going to fix that?

Only temporarily. Operators on higher-hour loaders and excavators with this engine report the same pattern: smoke shows up under load, an oil change knocks it back for a while, then it returns. That pattern points to worn liners or rings, not an oil-grade or filter problem, and it's worth a compression or blow-by check rather than repeat oil changes.

Where does this engine typically weep oil, and is it something to worry about?

The front crank seal, the accessory drive seal, and the cam follower housing area on the driver's side are the usual first spots. On an engine with real hours these are normal wear points, not a sign of a bigger internal problem — just keep an eye on the rate of the leak rather than assuming the worst.

What should we check before buying a used excavator or loader carrying this engine?

Pull the injector wiring harness connectors and look for corrosion, check the ECM's ground straps and battery fuse links, and note cranking behavior hot versus cold. Listen for injector clatter or a miss at idle. Ask for maintenance records showing whether the injector set was replaced together (rather than one at a time) and whether coolant was kept on spec — coolant neglect shows up later as liner pitting. Check the front seal and cam follower cover for oil weep, and pull whatever fault code history is available. Have your dealer verify engine hours line up with the wear you're seeing and confirm coolant additive compliance before you commit to the purchase.

Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.

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