Komatsuengine(no series)
Komatsu SAA6D125E-2D(S/N 210001-UP)
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu SAA6D125E-2D (S/N 210001-UP) is a turbocharged, air-to-air aftercooled diesel engine belonging to the 125-series family, primarily fitted to the PC450-6K crawler excavator. This mid-size excavator class machine typically operates in the 40-45 ton weight range, with production spanning the late 1990s into the early 2000s. The engine lineage traces back to the naturally aspirated 6D125E-2A and turbocharged S6D125E-2 variants used in the D65E-12 dozer series, evolving into the electronically controlled SAA6D125E-3 and SAA6D125E-5 generations. Configurations offered include standard-gauge and wide-gauge chassis options, with the SAA6D125E-2D specifically designated for the PC450LC-6K model starting at serial 210001.
Across the 125-series generations, the primary change was the transition from mechanical fuel systems and flyweight governors to electronically controlled unit injectors and advanced emissions packages. The SAA6D125E-2D remains significant in the used and parts market because it bridges the gap between simple, mechanically governed engines and modern complex ECUs. Its robust block design and straightforward diagnosis via warning lamps rather than fault codes make it a preferred candidate for rebuild. Buyers prioritize undercarriage and torque converter condition, as these wear items often dictate the machine's value more than the engine itself.
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 SAA6D125E-2D(S/N 210001-UP) specifications
Engine
| Model | SAA6D125E-7 |
| Gross/Net Power | 197 kW (264 hp) @ 1900 rpm (D85 Series); 268 kW (359 hp) @ 1900 rpm (PC490 Series) |
| Displacement | 11 L (674 in³) |
| Cylinders | 6 |
| Emissions Tier | Tier 4 Final / Stage V (per PC490 Series description) |
Weights
| Operating Weight | 29,300 - 31,688 kg (64,596 - 69,860 lb) (D85 Series) |
Dimensions
| Transport Length | Not documented for this exact serial range — verify with your dealer |
| Transport Width | Not documented for this exact serial range — verify with your dealer |
| Transport Height | Not documented for this exact serial range — verify with your dealer |
| Track Gauge | Not documented for this exact serial range — verify with your dealer |
| Ground Clearance | Not documented for this exact serial range — verify with your dealer |
Performance
| Travel Speeds | Not documented for this exact serial range — verify with your dealer |
| Digging Range | 16 - 17 m (52.5 - 55.8 ft) (PC490 Series) |
| Bucket Capacity | 5.9 - 14.1 m³ (7.7 - 18.4 cu yd) (D85 Series); 1.5 m³ (1.96 cu yd) (PC490 Series) |
Service capacities (summary)
| Fuel Tank | Not documented for this exact serial range — verify with your dealer |
| Hydraulic System | Not documented for this exact serial range — verify with your dealer |
| Engine Oil | Not documented for this exact serial range — verify with your dealer |
| Cooling System | Not documented for this exact serial range — verify with your dealer |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
SAA6D125E-2D(S/N 210001-UP) fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) | 38 L (10.0 US gal) | Komatsu Genuine diesel engine oil, EO10W30 or EO15W40 grade selected by ambient air temperature at startup per the OMM viscosity chart (roughly -30 deg C to +50 deg C range, 10W30 for colder end, 15W40 for warmer end); meets Komatsu EO engine-oil classification comparable to API CD/CF-4 duty. |
| Cooling system | 52 L (13.7 US gal) | Komatsu Genuine Supercoolant / Antifreeze Coolant AF-NAC, ethylene-glycol based, factory pre-mixed to a 50/50 ratio; change interval per OMM is 2 years or 4,000 hours, whichever comes first. |
| Fuel tank | 406 L (107.3 US gal) | Not documented for this exact serial range — verify with your dealer |
| Transmission/powertrain compartments | Not documented for this exact serial range — verify with your dealer | Not documented for this exact serial range — verify with your dealer |
| Final drives (each) | Not documented for this exact serial range — verify with your dealer | Not documented for this exact serial range — verify with your dealer |
| Hydraulic system AND tank | 55 L (14.5 US gal) | Not documented for this exact serial range — verify with your dealer |
| Axles/differentials | Not documented for this exact serial range — verify with your dealer | Not documented for this exact serial range — verify with your dealer |
| Grease | N/A | Not documented for this exact serial range — verify with your dealer |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Komatsu SAA6D125E-2D(S/N 210001-UP) maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 4,000 h |
|
Servicing the SAA6D125E-2D(S/N 210001-UP) beyond the schedule
Predictive Maintenance & Fluid Analysis
Pull engine oil and coolant samples on schedule for the SAA6D125E-2D. This 125-series turbocharged block has a known weep point between coolant and oil circuits; cross-contamination shows up in lab analysis before it appears on a dipstick. Watch torque converter temperature under load; a slow climb with no external leak points to an internal forward-clutch bypass, not a cooling-system fault. Track undercarriage wear (bushing, sprocket segment, shoe height) against OEM minimums each service interval, since undercarriage cost typically outpaces engine cost over the machine's life.
Corrective & Common Repairs
Oil showing up in coolant on this block usually traces to the oil cooler core, not a cracked head; pressure-test before committing to a gasket job. Torque converter overheating without an external leak is commonly a forward-clutch internal seal letting oil bypass the cooler, not a radiator fault. Weeping around the belly pan is typically a steering clutch or brake seal, hydraulic line, or pump gasket, not the engine itself. Dash and gauge dropouts trace to blown fuses, corroded connectors, or weak grounds behind the panel, not a failed sensor.
Overhaul & Rebuild Points
The SAA6D125E-2D is electronically controlled but retains a mechanically durable block, making it a straightforward rebuild candidate compared to later electronic engines. Resurface the head if a coolant weep has been running long enough to erode the surface; check the block for warpage after any overheating event. Match piston rings and liners to factory spec; mismatched aftermarket sets are a common cause of wear inside months, not years. On the undercarriage, segment-style sprockets let a shop renew worn tooth sections without pulling the whole final drive.
Seasonal & Environment Servicing
Select engine oil viscosity by ambient startup temperature per the OMM chart; run the lighter grade through cold snaps and the heavier grade once temperatures climb. Confirm the intake air heater and preheat lamp work before winter; a mechanically governed engine with no electronic cold-start assist depends on that circuit for starts. Keep coolant at the factory antifreeze concentration for freeze protection, not just topped with water. In hot, dusty conditions, clean radiator fins often and check track tension more frequently, since heat and abrasive ground both accelerate undercarriage wear.
SAA6D125E-2D(S/N 210001-UP) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 07281-00197 | Clamp,(With Pre-Fuel Filter) | Fuel system service | Check fitment → |
| 600-311-8293 | Cartridge, Fuel Filter | Fuel system service | Check fitment → |
| 6114-71-6202 | Fuel Filter Ass'Y | Fuel system service | Check fitment → |
| 6114-71-6210 | Head, Fuel Filter | Fuel system service | Check fitment → |
| 6125-81-7032 | Element Ass'Y,Air Cleaner | Air intake service | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
SAA6D125E-2D(S/N 210001-UP) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CA115 | Engine crankshaft speed sensor and backup speed sensor failure | Faulty speed sensor, broken wiring harness, or corroded connector at the pin connector | Replace the speed sensor and verify voltage at the pin connector |
| CA111 | Internal engine controller fault | ECM hardware malfunction or internal circuit failure | Replace or reprogram the ECM |
| CA451 | Common rail pressure sensor feedback value too high | Malfunctioning rail pressure sensor or actual overpressure condition in fuel lines | Diagnose the fuel rail pressure sensor and check pump lines |
| CA452 | Common rail pressure sensor feedback value too low | Faulty rail pressure sensor or low fuel supply pressure | Diagnose the fuel rail pressure sensor and check pump lines |
| CA122 | Intake air pressure sensor feedback voltage too high | Intake pressure sensor malfunction or wiring issue | Verify the intake pressure sensor and wiring |
| CA123 | Intake air pressure sensor feedback voltage too low | Sensor short circuit or airflow restriction | Check for a sensor short or an airflow restriction |
| CA153 | Intake air temperature sensor feedback voltage too high | Faulty intake air temperature (IAT) sensor | Replace or test the IAT sensor |
| CA154 | Intake air temperature sensor feedback voltage too low | Faulty intake air temperature (IAT) sensor | Replace or test the IAT sensor |
| CA234 | Engine overspeed | Throttle calibration error, engine load cycle issue, or operator misuse | Verify throttle calibration and engine load cycle |
| CA441 | Battery voltage too low | Weak battery, failing alternator, or voltage regulator issue | Replace the alternator or battery; check the voltage regulator |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
SAA6D125E-2D(S/N 210001-UP) attachments & work tools
Excavator Attachments
The SAA6D125E-2D engine powers the PC450LC-6K excavator class, which utilizes standard quick-coupler systems for bucket and breaker tooling. Typical bucket capacities for this size class range from 2.5 to 3.5 cubic meters depending on material density. Hydraulic breaker kits require high-flow auxiliary lines and specific pressure relief valves to match the machine's main pump output.
Dozer Blade Configurations
The D85 bulldozer series equipped with this engine family supports standard straight-tilt blades and wide-gauge low-ground-pressure configurations. Blade capacities for this class typically range from 5.9 to 7.0 cubic meters for earthmoving applications. Factory guarding options include heavy-duty side cutters and reinforced blade backs for abrasive terrain.
Wheel Loader Buckets
The WA450 and WA470 wheel loader models utilize quick-attach bucket systems compatible with standard 125-series engine platforms. Bucket capacities for these loaders generally fall between 3.0 and 4.0 cubic meters for general material handling. Hydraulic circuits for tilt and dump functions are integrated into the standard loader frame piping.
Hydraulic System Options
Work tool compatibility depends on the availability of auxiliary hydraulic circuits, which vary by machine model and factory spec. High-flow options are often required for heavy-duty breakers or hydraulic hammers. Verification of circuit pressure and flow rates is necessary to ensure proper tool operation and prevent pump damage.
All SAA6D125E-2D(S/N 210001-UP) assemblies by section
Every catalogued assembly group for the Komatsu SAA6D125E-2D(S/N 210001-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Engine
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : After Cooler (Ordering Transferdrd Parts)
| 61***90 | Clamp, Hose | 8 |
| 61***10 | Hose | 1 |
| 61***20 | Tube | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Air Cleaner
| 01***60 | Capscrew | 2 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 2 |
| 01***35 | Bolt,(F4320-52a0 -5 ) | 2 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Air Intke Manifold
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 2 |
| 01***30 | Bolt,(With Body Positioner) | 16 |
| 01***70 | Bolt - Bracket And Oil Inlet Tubemounting | 5 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Air Vent
| 07***12 | Gasket,(Without Air Compressor Type) (K2) | 12 |
| 07***10 | Screw, Banjo Connector (M10-1.25x20) | 6 |
| 61***60 | Tube,Air Vent | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Alternator (35a) (With Non Hardening Pulley) (Inner Parts)(#210085-)
| 60***51 | Alternator A. (35a) | 1 |
| KD***70 | Bushing,Insulate | 1 |
| KD***40 | Bushing,Insulate | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Alternator (50a) (With Non Hardening Pulley) (Inner Parts)
| 60***80 | Alternator A. (50a),(With Non Hardening Pulley) | 1 |
| SD***X0 | Pulley,Non Hardening | 1 |
| SD***X0 | Washer | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Alternator Mounting (35a) (With Non Haedening Pulley)(#210085-)
| 01***65 | Bolt - Return Line And Suction Linehose Clamps | 2 |
| 01***55 | Bolt - Mount Cage To Transmission Case | 1 |
| 01***55 | Bolt | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Alternator Mounting (50a) (With Non Haedening Pulley)
| 01***65 | Bolt - Return Line And Suction Linehose Clamps | 2 |
| 01***55 | Bolt - Mount Cage To Transmission Case | 1 |
| 01***55 | Screw | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Camfollower Cover
| 07***20 | Clamp, Spring Hose | 1 |
| 07***85 | Hose | 1 |
| 61***90 | O-Ring,Breather | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Camshaft
| 01***22 | Capscrew | 2 |
| 04***25 | Key, Plain Woodruff | 1 |
| 04***12 | Ring,Snap (For Ripper) | 12 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Cooling Fan
| 01***30 | Bolt,(With Body Positioner) | 12 |
| 60***70 | Fan,Cooling | 1 |
| 61***70 | Spacer | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Corrosion Resistor
| 01***16 | Bolt, Battery To Frame Ground Wire Attaching | 1 |
| 01***80 | Bolt,(With Corrosion Resistor) | 1 |
| 02***25 | Bolt,(Cold Weather Spec.) | 4 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Crank Pulley
| 01***30 | Screw | 1 |
| 01***35 | Screw | 5 |
| 04***28 | Pin, Dowel - Transmission Case, Pin-Dowel | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Crankshaft
| 61***10 | Bearing, Main (Standard) | 7 |
| 61***50 | Bearing, Thrust Assembly (Standard) | 1 |
| 61***10 | Bearing, Main (1.00mm Undersize) | 7 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Cylinder Block
| 01***12 | Bolt,(Without Air Compressor Type) | 2 |
| 01***20 | Bolt,(For Shipping) | 1 |
| 01***16 | Bolt, Mount Solenoid Valve | 6 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Cylinder Block Blind Cover And Plug
| 01***20 | Bolt,(For Mono Lever Steering) | 6 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 4 |
| 01***85 | Bolt, Divider Valve Mounting | 2 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Cylinder Block Gasket Kit
| 07***20 | O-Ring,Relief Valve | 1 |
| 07***21 | O-Ring,Water Piping | 1 |
| 07***30 | Ring, Seal - Between Sections | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Cylinder Head
| 01***20 | Bolt (M10-1.75x120) | 6 |
| 04***20 | Pin,Dowel (Welded) | 2 |
| 07***08 | Plug,(Without Lock-Up), Plug | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Cylinder Head Gasket Kit
| 07***65 | O-Ring,Cylinder Block | 6 |
| 07***12 | Gasket,Mechanical Pump Piping | 12 |
| 07***12 | Gasket,(Without Air Compressor Type) (K2) | 12 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Damper
| 01***25 | Bolt,(Without Rops Guard? Canopy) | 6 |
| 61***00 | Damper Assembly | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Electrical Wiring
| 01***10 | Bolt,(With Auto Emergency Steering) | 2 |
| 01***16 | Bolt, Battery To Frame Ground Wire Attaching | 2 |
| 01***20 | Bolt,(For Mono Lever Steering) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Exhaust Manifold
| 01***00 | Screw | 16 |
| 01***80 | Bolt | 2 |
| 07***08 | Plug,(Without Auto Priming System) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fan Drive
| 01***30 | Bolt,(With Body Positioner) | 4 |
| 01***15 | Bolt, Fan Mounting | 6 |
| 01***14 | Nut,(For Slag Handling) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fan Pulley
| 01***30 | Bolt,(With Body Positioner) | 6 |
| 04***62 | V-Belt Set,(For 35a? 50a Alternator) | 1 |
| 61***10 | Pulley?Non Hardening | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Flywheel
| 01***55 | Bolt | 6 |
| 01***45 | Washer,(For Travel Motor) (Not Show) | 6 |
| 61***51 | Gear, Ring | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Flywheel Housing
| 01***50 | Capscrew | 6 |
| 01***60 | Capscrew | 2 |
| 01***50 | Bolt,(Spark Arrester Spec.) | 2 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Front Cover
| 09***50 | Liquid Gasket, Lg-7, 150g | 0 |
| 61***30 | Seal? Front (K2) | 1 |
| 61***41 | Cover,Front | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Front Cover Related Parts
| 01***30 | Bolt,(With Body Positioner) | 1 |
| 01***65 | Bolt - Return Line And Suction Linehose Clamps | 7 |
| 01***70 | Bolt - Bracket And Oil Inlet Tubemounting | 4 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Filter
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 3 |
| 01***30 | Bolt,(With Body Positioner) | 1 |
| 01***50 | Bolt,(Spark Arrester Spec.) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Injection Pump (Coupling) (Inner Parts)
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Injection Pump (Feed Pump) (Inner Parts)
| DK***20 | Bolt, Joint | 1 |
| DK***00 | Valve,Check | 2 |
| DK***30 | Feed Pump Assembly | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Injection Pump (Governor) (1/2) (Inner Parts)
| DK***00 | Gasket | 1 |
| DK***20 | Flyweight Ass'Y | 1 |
| DK***00 | Shim? 2.00mm,(High Altitude Spec.) | 0 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Injection Pump (Governor) (2/2) (Inner Parts)
| DK***80 | Shim? 0.5mm | 0 |
| DK***00 | Washer,Spring | 1 |
| DK***80 | Bolt,Eye | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Injection Pump (Pump) (1/2) (Inner Parts)
| 61***80 | Injection Pump Ass'Y | 1 |
| DK***30 | Bearing,Roller | 2 |
| DK***20 | Housing | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Injection Pump (Pump) (2/2) (Inner Parts)
| DK***00 | Shim? 0.875mm | 0 |
| DK***00 | Shim? 0.500mm | 0 |
| DK***00 | Shim? 1.575mm | 0 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Injection Pump (Timer) (Inner Parts)
| DK***00 | O-Ring | 1 |
| DK***00 | Gasket | 1 |
| DK***00 | Plug | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Injection Pump Drive
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 4 |
| 01***14 | Nut (Itl) | 1 |
| 01***60 | Washer,(Without Rops Guard? Canopy) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Injection Pump Mounting
| 01***90 | Bolt,(For No?1 And No?3 Housing) | 4 |
| 01***16 | Washer,(With Water Separator) | 4 |
| 07***10 | Connector, Grease Fitting | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Injection Pump Piping
| 01***30 | Screw | 1 |
| 01***45 | Bolt,(With Water Separator Type) | 2 |
| 01***55 | Bolt,(See Service News) | 4 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Pre Filter(#210085-)
| 01***25 | Bolt,(Rear Attachment Less) | 2 |
| 01***30 | Bolt,(With Body Positioner) | 2 |
| 01***23 | Washer, Wiring Harness Mounting Bracket | 2 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Fuel Return
| 01***20 | Bolt,(For Mono Lever Steering) | 1 |
| 01***16 | Washer,Radio Controlled Slag Handling | 2 |
| 04***10 | Clip,(With Accumulator) | 2 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Head Cover
| 01***16 | Washer,Radio Controlled Slag Handling | 24 |
| 61***11 | Cover,Head? No.2?3?4?5?6 | 5 |
| 61***51 | Cover,Head? No.6 | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Head Cover Mounting (Cap)
| 07***50 | Cap,Oil Filler | 1 |
| 61***20 | Tube | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Hose And Clip (Ordering Transferded Parts)
| 07***50 | Hose, Right | 1 |
| 07***55 | Clip,94 | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Idler Gear
| 01***60 | Capscrew | 1 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 6 |
| 61***60 | Pin, Dowel | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Injection Nozzle
| 01***45 | Bolt, Mount Divider Valve | 12 |
| 07***65 | O-Ring,Cylinder Block | 6 |
| 07***12 | Gasket,(Without Air Compressor Type) (K2) | 12 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Muffler
| 01***20 | Bolt,(For Mono Lever Steering) | 1 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 4 |
| 01***40 | Bolt (Op) | 4 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Name Plate And Caution Plate
| 04***50 | Screw | 4 |
| 09***63 | Plate? Instruction,Air Cleaner (Single Element) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Nozzle Holder (Inner Parts)
| 07***12 | Gasket,Mechanical Pump Piping | 2 |
| 61***52 | Bolt, Joint | 1 |
| 61***10 | Fuel Injector Assembly | 6 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Oil Adapter
| 01***35 | Bolt,(F4320-52a0 -5 ) | 2 |
| 01***50 | Bolt,(Spark Arrester Spec.) | 4 |
| 01***08 | Nut,(For Canvas Canopy?Head Guard) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Oil Cooler
| 01***25 | Bolt - Relay Mounting | 2 |
| 07***42 | O-Ring,(See Fig.A3310) | 1 |
| 61***25 | Cover | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Oil Cooler Mounting Parts
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 12 |
| 01***65 | Bolt - Return Line And Suction Linehose Clamps | 2 |
| 01***80 | Bolt,(With Corrosion Resistor) | 2 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Oil Filter
| 01***30 | Bolt,(With Body Positioner) | 3 |
| 01***80 | Bolt,(With Corrosion Resistor) | 4 |
| 07***35 | O-Ring,Transmission Valve Mount | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Oil Level Gauge
| 01***20 | Bolt,(For Mono Lever Steering) | 1 |
| 01***08 | Nut, Regular Hexagon (M10-1.50) | 1 |
| 01***16 | Washer,Radio Controlled Slag Handling | 2 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Oil Pan And Suction Tube
| 01***20 | Bolt,(For Mono Lever Steering) | 1 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 27 |
| 01***30 | Bolt,(With Body Positioner) | 8 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Oil Pump
| 01***25 | Bolt,(Rear Attachment Less) | 4 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 3 |
| 01***35 | Bolt,(F4320-52a0 -5 ) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Piston
| 02***13 | Pin, Dowel | 2 |
| 04***18 | Ring, Snap | 12 |
| 61***30 | Bushing,(Service Part) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Rocker Arm
| 01***75 | Screw | 37 |
| 01***90 | Bolt,(For No?1 And No?3 Housing) | 2 |
| 01***08 | Nut,R.H. Thread | 12 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Safety Guard (For Fuel Injection Pump Drive)(#210002-)
| 01***20 | Bolt,(For Mono Lever Steering) | 2 |
| 61***51 | Cover,Safety | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Starting Motor (11kw) (Inner Parts)
| 60***11 | Starting Motor Ass'Y,(11kw) | 1 |
| KD***40 | Spring,Spring | 4 |
| KD***57 | Bearing, Ball, Front | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Starting Motor Mounting (11kw)
| 01***40 | Bolt,(For Slag Handling) (For Usa) | 3 |
| 01***35 | Bolt, Mount Bracket To Floor | 1 |
| 01***32 | Washer,(With Auto Emergency Steering) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Tachometer Drive
| 01***75 | Screw | 2 |
| 01***32 | Washer,(With Auto Emergency Steering) | 2 |
| 61***31 | Gear,(With Air Compressor Type) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Turbocharger (Inner Parts)
| 61***20 | Turbocharger Ass'Y | 1 |
| SP***49 | V-Clamp | 1 |
| SP***65 | Nut, Lock | 2 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Turbocharger Oil Piping
| 01***20 | Bolt, Wiring Harness Mounting Bracket | 2 |
| 01***30 | Bolt - M8 X 30lg | 2 |
| 01***20 | Bolt,(For Mono Lever Steering) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Water Drain Valve
| 07***80 | Clamp, Drain Hose | 1 |
| 07***25 | Hose,Drain | 1 |
| 20***30 | Valve,Heat Water Inlet | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Water Pump
| 01***16 | Bolt - Seat And Tether Belt Mounting | 6 |
| 01***20 | Bolt,(For Mono Lever Steering) | 2 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 2 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Water Pump Gasket Kit
| 02***37 | O-Ring,(For Pc750?1800) (A5010) | 1 |
| 07***15 | O-Ring,(F4320-57a0 -11 ) | 1 |
| 61***90 | Gasket (K2?K6) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Water Separator And Piping(#210083-)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 2 |
| 01***30 | Bolt,(With Body Positioner) | 2 |
| 01***16 | Washer,Radio Controlled Slag Handling | 2 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Water Separator And Piping(#210085-)
| 01***30 | Bolt,(With Body Positioner) | 2 |
| 01***16 | Washer,Radio Controlled Slag Handling | 2 |
| 04***10 | Clip,(Without Cab) | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Water Separator(#210083-)
| 07***12 | Gasket,Mechanical Pump Piping | 1 |
| 60***90 | O-Ring | 1 |
| 60***90 | Plug,Drain | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Water Separator(#210085-)
| 07***12 | Gasket,Mechanical Pump Piping | 1 |
| 60***90 | O-Ring | 1 |
| 60***90 | Plug,Drain | 1 |
Komatsu : Saa6d125e-2d(S/N 210001-Up) : Engine : Water Temperature Sensor
| 78***20 | Sensor, Trans. Control Valve Oil Temperature | 1 |
SAA6D125E-2D(S/N 210001-UP) serial number reference
The engine serial plate is riveted to the left side of the engine block near the injection pump. The prefix is the first character of the 6-digit machine serial number stamped on the front frame between the hydraulic arms.
| Prefix | Identifies | Notes |
|---|---|---|
| K | PC450LC-6K | Serial range K30001-Up. Source: Equipment Guide PDF. Verify with dealer. |
| M | PC450LC-6K-KE | Serial range 32106-Up. Source: Equipment Guide PDF. Verify with dealer. |
Frequently asked questions
What is the engine model for the Komatsu PC450-6K (S/N 210001-UP)?
The engine model is the Komatsu SAA6D125E-2D.
What is the operating weight of the Komatsu PC450-6K?
The operating weight varies by configuration/series, typically ranging from 40,000 to 45,000 kg (88,185-99,208 lb) depending on the boom, stick, and counterweight setup.
What engine replaced the SAA6D125E-2D?
The SAA6D125E-3 and subsequent SAA6D125E-5 series replaced the SAA6D125E-2D, featuring electronically controlled fuel systems and advanced emissions compliance.
What SAA6D125E-2D(S/N 210001-UP) owners discuss
What are the known powertrain and hydraulic behaviors for the Komatsu SAA6D125E-2D engine?
The engine is a six-cylinder, turbocharged, air-to-air aftercooled diesel unit. It delivers approximately 275 horsepower (205 kilowatts) with a torque of 1,010 pound-feet (1,370 Newton meters). The fuel system utilizes a Bosch-style injection setup with injectors operating at 3,200 PSI. Hydraulic systems in machines equipped with this engine are known for strong performance but can suffer from priority valve issues that prevent simultaneous function operation if leakage occurs. Fuel consumption at rated power is approximately 18.5 gallons per hour (70 liters per hour). Powertrain components such as final drives and steering clutches are splash-lubricated and lack independent filtration, requiring careful monitoring of oil condition for wear metals.
What undercarriage or wear patterns are typical for machines using this engine series?
Machines equipped with the SAA6D125E series, such as the PC450 and PC490 excavators, are heavy-duty units designed for mass excavation. Undercarriage wear is accelerated by continuous load and dust exposure. The X-frame structure provides stability on uneven terrain but requires regular inspection of track tension and roller alignment. Operators report that slow hydraulic movements and sluggish controls often indicate internal leakage or priority valve issues rather than undercarriage failure, but track shoe wear and final drive grinding noises are common indicators of heavy use in mining and construction applications.
What are the engine quirks per the SAA6D125E-2D series?
The SAA6D125E-2D is part of the 125-series block family. A known quirk in the broader 125-series naturally aspirated variants is a weep point between coolant and oil circuits; cross-contamination often appears in lab analysis before visible signs on the dipstick. For the turbocharged SAA6D125E variants, the engine relies on hardened cylinder liners matched to high-alloy piston rings. Operators note that the engine is robust but sensitive to fuel system integrity; a missing key on the fuel pump drive gear shaft can cause low-side pressure loss under load, leading to poor performance. The engine uses wet cylinder liners, making supplemental coolant additive maintenance critical to prevent cavitation pitting.
What are common electrical or sensor issues reported for this engine?
Komatsu excavators with this engine rely heavily on electronic control systems. Common issues include intermittent starting, dashboard failures, and random shutdowns triggered by faulty sensors or unstable power supplies. Specific sensor failures include the oil pressure sensor, which can cause low oil pressure warnings even when levels are correct. Intake air temperature and coolant temperature sensor feedback faults are frequent diagnostic codes. The Electronic Control Module (ECM) monitors these sensors, and a single faulty sensor can trigger multiple warning signals across the machine. Network failures and engine controller power issues are also documented causes of engine stall or reduced output.
What should be checked when buying a used machine with the SAA6D125E-2D engine?
Verify the serial number prefix 210001-UP to confirm the engine variant. Check for signs of coolant contamination in the oil (milky oil or steam from the breather), which indicates liner or oil cooler core failure. Inspect the fuel pump drive gear key for integrity. Test the oil pressure sensor and gauge for accuracy. Check the torque converter temperature under load to detect internal forward-clutch bypass. Review maintenance history for supplemental coolant additive levels. Inspect the undercarriage for wear and listen for grinding noises in the final drives. Verify the condition of the air cleaner and radiator core for debris blockage.
What fluids are specified for the Komatsu SAA6D125E-2D engine and related systems?
Komatsu specifies Komatsu Genuine Oil (KOWA) for engine lubrication. Hydraulic systems require Komatsu Hydraulic Oil (HYDO). Axle and transmission systems use Komatsu Axle Oil (AXO) or Powertrain Oil (HO). Cooling systems utilize Super-coolant AF-NAC. Operators are advised to perform Komatsu Oil Wear Analysis (KOWA) on scheduled intervals to monitor engine health.
What is a safety-critical fix associated with the fuel system on this engine series?
Ensure the fuel pump drive gear is securely keyed to the shaft. A missing key can cause the low side of the fuel pump to lose pressure under load, leading to engine stalling or severe performance loss. Have your dealer verify the fuel pump assembly and drive gear key integrity before operation.
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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