Komatsu 3D84-2GA(S/N 00292-UP)
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu 3D84-2GA engine is a vertical, water-cooled, 4-stroke, 3-cylinder diesel powerplant with a displacement of 1.496 liters (1496 cc) and a bore of 84 mm. It produces 38 hp at 2700 rpm. This engine is primarily used in compact construction machinery, including mini excavators such as the Komatsu PC30 MR 2 and skid steer loaders like the SK 510-5. The 3D84 series has been manufactured by Komatsu since 2017, serving as a reliable power source for utility and light earthmoving applications where compact dimensions and moderate weight are required for integration into smaller machine designs.
Across the 3D84 series generations, the engine has maintained its core 3-cylinder architecture while adapting to evolving emissions standards and operational demands. The 3D84-2GA variant specifically supports the durability and efficiency needs of the used mini excavator and skid steer market. Its compact size and reliable performance make it a critical component for fleet maintenance in the secondary market, where availability of specific overhaul kits and genuine lubricants ensures extended machine life. The engine's design allows for easy integration into various chassis configurations, maintaining Komatsu's reputation for robust industrial power in the compact equipment segment.
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 3D84-2GA(S/N 00292-UP) specifications
Engine
| Model | 3D84-2GA |
| Configuration | Vertical, water-cooled, 4-stroke, 3-cylinder inline diesel |
| Displacement | 1.496 L (91.3 cu in) |
| Bore x Stroke | 84 x 90 mm |
| Gross/Net Power | 38 hp @ 2,700 rpm |
| Emissions Tier | Not documented for this exact serial range — verify with your dealer |
Weights
| Operating Weight | Not documented for this exact serial range — verify with your dealer |
| Shipping Weight | Not documented for this exact serial range — verify with your dealer |
| Ground Pressure | Not documented for this exact serial range — verify with your dealer |
Dimensions
| Transport Length/Width/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 |
| Dig/Dump/Lift/Drawbar | Not documented for this exact serial range — verify with your dealer |
| Gradeability | Not documented for this exact serial range — verify with your dealer |
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.
Komatsu 3D84-2GA(S/N 00292-UP) maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the 3D84-2GA(S/N 00292-UP) beyond the schedule
Predictive Maintenance & Fluid Analysis
Utilize KOWA fluid analysis at every major service interval to monitor engine wear metals (iron, copper, lead, aluminum) and contaminants (silicon, sodium). Check coolant pH, SCA concentration, and glycol content to prevent corrosion in the 3D84-2GA's water-cooled block. Monitor hydraulic fluid particle count and viscosity to protect the machine's high-pressure pumps. Regularly inspect the air filter restriction indicator to ensure clean intake air, preserving the 3-cylinder engine's efficiency and preventing premature wear on the 1.496-liter displacement components.
Corrective & Common Repairs
Address fuel system issues by regularly draining the water separator and replacing the fuel filter to protect the 3D84-2GA's injection system. Inspect the turbocharger and exhaust system for leaks or damage during 1000-hour services. Check belt and hose conditions for cracks or wear, replacing them before failure to avoid overheating or loss of power. Monitor battery terminals and load test the battery to ensure reliable starts. Inspect hydraulic hoses for leaks and replace worn lines to maintain system pressure and prevent fluid loss in the compact excavator or skid steer chassis.
Overhaul & Rebuild Points
Plan for major engine overhaul based on wear measurements and fluid analysis results. The 3D84-2GA requires specific overhaul kits compatible with its 3-cylinder configuration. Inspect cylinder liners, pistons, and bearings for wear. Check valve guides and seats for leakage. Replace all gaskets and seals during rebuild. Ensure proper torque specifications for the cylinder head and oil pan. Use Komatsu Genuine Lubricants during reassembly to protect the engine's precision components and ensure optimal performance in the compact machinery application.
Seasonal & Environment Servicing
In cold climates, check coolant concentration and glycol content to prevent freezing in the 3D84-2GA's cooling system. Inspect battery health and charge level, as cold temperatures reduce cranking power. In hot environments, ensure the radiator and oil cooler fins are clear of debris to prevent overheating. Check air filter condition more frequently in dusty conditions to protect the 3-cylinder engine. Monitor hydraulic fluid temperature and viscosity, adjusting fluid selection if necessary for extreme ambient temperatures to maintain machine performance and component longevity.
3D84-2GA(S/N 00292-UP) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| YM129100-55650 | Element,Fuel Filter | Fuel system service | Check fitment → |
| YM129100-55621 | Fuel Filter Ass'Y | Fuel system service | Check fitment → |
| YM102103-55520 | O-Ring,(For Fuel Filter) | Fuel system service | Check fitment → |
| YM129436-12900 | Element,Outer | Scheduled service item | Check fitment → |
| YM129436-12910 | Element,Inner | Scheduled service item | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
3D84-2GA(S/N 00292-UP) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CA115 | Engine crankshaft speed sensor failure | Broken sensor, wiring issue, or connector corrosion | Replace the speed sensor and verify voltage at the pin connector |
| CA111 | Internal engine controller fault | ECM hardware failure | Replace or reprogram the ECM |
| CA441 | Battery voltage too low | Weak battery, poor connections, or alternator failure | Replace the alternator or battery; check the voltage regulator |
| CA442 | Battery voltage too high | Faulty voltage regulator or alternator overcharging | Replace the alternator or battery; check the voltage regulator |
| CA122 | Intake air pressure high voltage | Sensor malfunction or actual overpressure condition | Verify the intake pressure sensor and wiring |
| CA123 | Intake air pressure low voltage | Sensor short or airflow restriction | Check for a sensor short or an airflow restriction |
| CA153 | Intake air temperature sensor error (High) | Sensor failure or wiring issue | Replace or test the IAT sensor |
| CA154 | Intake air temperature sensor error (Low) | Sensor failure or wiring issue | Replace or test the IAT sensor |
| CA428 | Fuel moisture sensor invalid voltage (High) | Contaminated fuel or sensor harness fault | Ensure a clean fuel supply, and check the moisture sensor harness |
| CA429 | Fuel moisture sensor invalid voltage (Low) | Contaminated fuel or sensor harness fault | Ensure a clean fuel supply, and check the moisture sensor harness |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
3D84-2GA(S/N 00292-UP) attachments & work tools
Buckets
Standard and heavy-duty digging buckets are the primary work tools for this mini excavator class. Typical capacities range from 0.3 to 0.5 cubic meters (0.4 to 0.7 cubic yards) depending on material density and machine configuration. Factory guarding options include side cutters and wear strips to extend bucket life in abrasive conditions.
Hydraulic Breakers
Hydraulic breakers are supported by the machine's auxiliary hydraulic circuit. Coupler systems typically use a quick-attach pin or a proprietary quick-coupler interface for tool changes. Hydraulic kit requirements depend on the breaker model, often necessitating specific flow and pressure settings to match the engine's output.
Grapples and Clamps
Rotating grapples and material clamps are available for handling debris, brush, or scrap. These tools utilize the standard hydraulic quick-attach mounting system. Hydraulic flow requirements vary by grapple size and cylinder configuration, requiring verification against the machine's auxiliary pump capacity.
Augers
Post-hole augers are used for fencing and light construction tasks. They mount via the standard quick-attach system and require auxiliary hydraulic flow to drive the rotation. Typical diameters range from 300 to 600 millimeters (12 to 24 inches), with depth capabilities determined by the stick length.
Tilt Rotators
Tilt rotators provide enhanced precision for grading and fine digging. They replace the standard quick-attach coupler, integrating hydraulic lines for both rotation and tilt functions. This configuration requires compatible hydraulic hoses and flow control valves to operate the additional axes of movement.
All 3D84-2GA(S/N 00292-UP) assemblies by section
Every catalogued assembly group for the Komatsu 3D84-2GA(S/N 00292-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Accessory
Komatsu : 3d84-2ga(S/N 00292-Up) : Accessory : P.P.C. Pump And Mounting(#03321-)
| YM***20 | Pump Ass'Y,Hydraulic | 1 |
| YM***80 | Gasket (Kit) | 1 |
| YM***81 | Gasket (Kit) | 1 |
Cooling System
Komatsu : 3d84-2ga(S/N 00292-Up) : Cooling System : Water Pump And Cooling Fan(#18428-)
| YM***20 | Gasket,Water Pump | 1 |
| YM***52 | Screw | 4 |
| YM***30 | Cover | 1 |
Cylinder Block
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Block : Camshaft And Tappet(#03321-)
| YM***80 | Camshaft Ass'Y | 1 |
| YM***01 | Gear Ass'Y,Camshaft | 1 |
| YM***50 | Bearing, Thrust | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Block : Crankshaft(#18428-)
| YM***00 | Gear,Crank | 1 |
| YM***80 | Parallel Pin | 1 |
| YM***00 | Crankshaft Ass'Y | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Block : Cylinder Block(#18428-)
| YM***20 | Plug,Drain(Without Oil Cooler Type) | 1 |
| YM***20 | Screw | 8 |
| YM***00 | Plug | 2 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Block : Flywheel And Flywheel Housing(#03321-)
| YM***02 | Screw | 6 |
| YM***02 | Screw | 4 |
| YM***80 | Parallel Pin | 4 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Block : Front Cover And Gear(#18428-)
| YM***90 | Front Cover Ass'Y | 1 |
| YM***10 | Washer,Seal | 5 |
| YM***51 | Cap, Lub. Oil Supply | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Block : Oil Pan(#18428-)
| YM***02 | Screw | 4 |
| YM***40 | O-Ring,Drain Plug | 1 |
| YM***52 | Screw | 2 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Block : Piston And Connecting Rod(#03321-)
| YM***20 | Piston Ass'Y | 3 |
| YM***00 | Screw | 2 |
| YM***00 | Crank Pin Metal A. (Std) | 1 |
Cylinder Head
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Head : Air Cleaner And Mounting (Double Element Type)(#03321-)
| YM***41 | Buffle | 1 |
| YM***10 | Cap | 1 |
| YM***30 | Pan,Dust | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Head : Air Cleaner And Mounting (Single Element Type)(#18428-)
| YM***41 | Buffle | 1 |
| YM***10 | Cap | 1 |
| YM***30 | Pan,Dust | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Head : Air Intake Manifold And Connection(#03321-)
| YM***01 | Heater,Intake Air | 1 |
| YM***00 | Manifold,Air Intake | 1 |
| YM***11 | Gasket,Intake Manifold | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Head : Cylinder Head Cover(#03321-)
| YM***20 | Cover, Breather | 1 |
| YM***51 | Cap, Lub. Oil Supply | 1 |
| YM***00 | Clip,Breather Hose | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Head : Cylinder Head(#03321-)
| YM***80 | Retainer, Spring | 6 |
| YM***40 | Seal,Valve? Exhaust (Kit) | 3 |
| YM***10 | Valve,Exhaust | 3 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Head : Exhaust Manifold And Muffler(#18428-)
| YM***10 | Manifold, Exhaust | 1 |
| YM***60 | Support,R.H | 1 |
| YM***01 | Gasket (Kit) | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Cylinder Head : Rocker Arm(#03321-)
| YM***02 | Screw | 6 |
| YM***80 | Spring | 3 |
| YM***50 | Rocker Arm Ass'Y | 6 |
Electrical System
Komatsu : 3d84-2ga(S/N 00292-Up) : Electrical System : Alternator (40a)(#03321-)
| YM***50 | Brush Ass'Y | 1 |
| YM***00 | Retainer,Bearing | 1 |
| YM***70 | Diode Ass'Y | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Electrical System : Alternator And Mounting (40a)(#18428-)
| YM***02 | Nut | 1 |
| YM***02 | Nut | 1 |
| YM***00 | Washer,Spring | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Electrical System : Safety Relay(#03321-)
| YM***00 | Relay, Safety | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Electrical System : Starting Motor (1.8kw)(#03321-)
| YM***40 | Bolt,Through | 2 |
| YM***50 | Pinion Ass'Y,Pinion | 1 |
| YM***00 | Cover,Rear | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Electrical System : Starting Motor And Mounting (1.8kw)(#03321-)
| YM***52 | Bolt Plated | 2 |
| YM***02 | Nut,Rock | 1 |
| YM***00 | Washer,Spring | 1 |
Fuel System
Komatsu : 3d84-2ga(S/N 00292-Up) : Fuel System : Engine Stop Motor And Mounting(#18428-)
| YM***20 | Motor Ass'Y,Engine Stop | 1 |
| YM***80 | Ring,Snap | 1 |
| YM***00 | Pin,Cotter | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Fuel System : Fuel Filter And Piping(#03321-)
| YM***70 | Union | 1 |
| YM***10 | Hose,(See Fig.0415-17?0416-17) | 1 |
| YM***00 | O-Ring (Kit) | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Fuel System : Fuel Injection Pump (Governor) (1/2)(#03321-)
| YM***02 | Lever Ass'Y,Stop | 1 |
| YM***10 | Pin,Stop Lever | 1 |
| YM***00 | O-Ring (Kit) | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Fuel System : Fuel Injection Pump (Governor) (2/2)(#03321-)
| YM***01 | Weight Assembly., Governor | 1 |
| YM***90 | Shaft,Governor Lever | 1 |
| YM***50 | Angleich Ass'Y | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Fuel System : Fuel Injection Pump (Pump) (1/2)(#03321-)
| YM***90 | Injection Pump Ass'Y | 1 |
| YM***50 | Kit, Shim | 1 |
| YM***10 | Plate? Caution | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Fuel System : Fuel Injection Pump (Pump) (2/2)(#03321-)
| YM***70 | Retainer, Spring | 3 |
| YM***00 | Plunger Ass'Y | 3 |
| YM***02 | Screw | 2 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Fuel System : Fuel Injection Pump And Piping(#03321-)
| YM***20 | Retainer, Pipe | 1 |
| YM***60 | O-Ring,Fuel Injection Pump | 1 |
| YM***30 | Bolt | 2 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Fuel System : Fuel Nozzle And Spill Pipe(#03321-)
| YM***20 | Spring | 1 |
| YM***00 | Fuel Injection Nozzle, Assembly | 1 |
| YM***80 | Seat,Nozzle (Kit) | 3 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Fuel System : Water Separator(#18428-)
| YM***00 | Gasket | 2 |
| YM***00 | O-Ring (Kit) | 1 |
| YM***50 | Plug,Air | 2 |
Lubricating Oil System
Komatsu : 3d84-2ga(S/N 00292-Up) : Lubricating Oil System : Lubricating Oil Filter And Mounting(#18428-)
| YM***50 | Nut | 1 |
| YM***02 | Bolt Plated | 3 |
| YM***00 | Valve,Relief | 1 |
Komatsu : 3d84-2ga(S/N 00292-Up) : Lubricating Oil System : Lubricating Oil Pump And Piping(#03321-)
| YM***50 | Oil Pressure Transmitter | 1 |
| YM***40 | Gasket,Inlet Pipe | 1 |
| YM***41 | Gasket (Kit) | 1 |
Tool And Engine Kit
Komatsu : 3d84-2ga(S/N 00292-Up) : Tool And Engine Kit : Gasket Kit(#03321-)
| YM***60 | O-Ring,Fuel Injection Pump | 1 |
| YM***20 | Gasket,Water Pump | 1 |
| YM***10 | Gasket (Kit) | 1 |
Frequently asked questions
What engine does the Komatsu 3D84-2GA use?
The Komatsu 3D84-2GA is a vertical, water-cooled, 4-stroke, 3-cylinder diesel engine with a displacement of 1.496 liters (1496 cc) and a bore of 84 mm. It produces 38 hp at 2700 rpm.
What is the operating weight of the machine using this engine?
Operating weight varies by configuration and series. For the specific machine class using the 3D84-2GA, such as the PC30 MR 2 excavator or SK 510-5 skid steer, weights fall within the compact equipment range, typically under 20,000 lbs, but exact figures vary by configuration/series.
What replaced the Komatsu 3D84-2GA?
The 3D84 series has been in production since 2017. Specific successor models are not documented for this exact serial range in the provided sources. Verify with your dealer for the latest engine replacements in the compact equipment line.
Need a specific 3D84-2GA(S/N 00292-UP) part?
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