Komatsuengine(no series)

Komatsu 4D88E-3B(S/N 00101-UP)

Maintenance schedule, common problems & OEM parts breakdown

Search live 4D88E-3B(S/N 00101-UP) parts

The Komatsu 4D88E-3B(S/N 00101-UP) is a standalone industrial diesel engine, not a complete machine — a vertical inline 4-cylinder, 4-cycle, water-cooled unit displacing 2.189 L (133.6 cu in) from an 88 mm x 90 mm (3.46 in x 3.54 in) bore and stroke. It is naturally aspirated with mechanical direct injection and a flyweight governor, built on the Yanmar 4TNE88 base block under license. Family-level output for this naturally aspirated dash-3 generation runs roughly 27-29 kW (36-39 hp) at a 2350-2500 rpm governed speed; the exact rating for the -3B letter suffix specifically is not separately published, so treat it as a class range and confirm against the engine data plate. -3B is one of several dash-3 sub-configurations (3A, 3C, 3D, 3GB, 3H) built for different original-equipment fitments of the same core block, differing mainly in starter, alternator, and accessory-drive fit-out rather than displacement or output. This engine family powered a range of Komatsu-badged compact machines from the late 1980s into the 1990s, including mini hydraulic excavators, mini skid-steer loaders, and tracked mini-carrier/dumper units in the 2-6 tonne class; exact original-equipment assignment for this specific 00101-UP serial book is not independently confirmed, so treat host coverage as class-level rather than machine-specific.

The dash-3 generation is a mechanical, pre-emissions design — jerk-type injection pump, flyweight governor, no engine control module — predating the electronically governed, EPA/Tier-certified dash suffixes (5, 5X, 6, and ultimately the Tier 4 Final 7) built later on the same base architecture, which added electronic fuel control and, by the -7, exhaust gas recirculation and a diesel particulate filter. Sub-suffix letters within the dash-3 generation (3A/3B/3C/3D/3GB/3H) mark original-equipment running changes and accessory fit-out rather than a technical redesign. In the used and parts market, the -3B and its dash-3 siblings stay in demand as simple, low-cost replacement power for older compact excavators, skid steers, and carriers still working — no ECM, no aftertreatment, and no DEF system to fail keeps rebuild and swap costs down and keeps good used cores valuable for like-for-like engine replacement.

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 4D88E-3B(S/N 00101-UP) specifications

Engine

Engine family	4D88E-3 series industrial diesel (covers the 3A/3B/3C/3D/3GB/3H configuration variants of this dash generation); the -3B is a configuration variant within this generation, differing from siblings mainly in equipment fit-out rather than core output.
Configuration	Vertical inline 4-cylinder, 4-cycle, water-cooled diesel, naturally aspirated, direct injection.
Displacement	2.189 L (133.6 cu in).
Bore x stroke	88 mm x 90 mm (3.46 in x 3.54 in).
Power output	Not separately published for the 3B dash suffix. Comparable Komatsu-installed configurations of this engine family (naturally aspirated, non-turbo) are documented at roughly 29 kW (39 hp) gross and 27-28 kW (36-38 hp) net at 2350-2500 rpm governed speed. Treat as a family-level range; varies by configuration/application, not a confirmed 3B-specific rating.
Emissions status	This dash-3 generation is a mechanical, pre-emissions-tier design, predating the later EPA/Tier-certified dash suffixes (5X, 6, 7) built on the same base block.
Base platform	Shares its core block architecture with the Yanmar 4TNE88 industrial diesel, built under license.

Weights

Engine dry weight	Approximately 170 kg (374 lb) for the base long block, typical of this engine platform. Fitted weight varies with radiator, alternator, starter and other accessories added for a given installation.
Shipping/operating weight	Not published as a standalone figure for this configuration; this is a power-unit engine, not a complete machine, so no operating weight applies.

Dimensions

Engine length	Approximately 630 mm (24.8 in), base long-block figure typical of this platform.
Engine width	Approximately 500 mm (19.7 in).
Engine height	Approximately 620 mm (24.4 in).
Machine-level dimensions	Transport length/width/height, wheelbase, track gauge and ground clearance do not apply to this standalone engine; those figures belong to the specific host machine it is installed in, not to the engine itself.

Performance

Aspiration	Naturally aspirated, no turbocharger.
Fuel system	Mechanical direct injection.
Compression ratio	Approximately 18:1, consistent across this engine platform.
Governed rated speed	Approximately 2350-2500 rpm in comparable Komatsu-installed configurations; exact governed speed depends on the specific application and dash configuration.
Machine performance figures	Travel speed, drawbar, lift/dig/dump and gradeability figures do not apply to this standalone engine; they belong to the host machine it powers.

Service capacities (summary)

Engine oil capacity	Approximately 7.9-8.3 L (8.3-8.8 US qt), typical for this engine platform including filter.
Cooling system capacity	Approximately 2.7-2.8 L (2.9-3.0 US qt).
Fuel tank / hydraulic system	Not applicable; this is a bare power-unit engine with no onboard fuel tank or hydraulic system. Those capacities belong to the host machine it is installed in.

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

4D88E-3B(S/N 00101-UP) fluids & capacities

System	Capacity	Recommended fluid
Engine crankcase (oil pan, with filter change)	7.9 L (8.3 US qt / 2.1 US gal)	Komatsu Genuine engine oil (EO series) or an equivalent diesel engine oil meeting API CC or higher. Use SAE 10W-30 for normal and warm ambient conditions; switch to SAE 5W-20 in cold winter climates for easier starting. Check level with the engine stopped on level ground, between the dipstick marks.
Cooling system (radiator and block)	2.7 L (2.8 US qt / 0.7 US gal)	Komatsu Supercoolant AF-NAC, or an equivalent ethylene-glycol based antifreeze/coolant, maintained at a 50/50 premix for year-round freeze and corrosion protection. Check level at the reserve tank with the engine cold.
Fuel system	No fixed engine capacity — this engine ships without an integral fuel tank; usable capacity is set by the tank on the equipment it is installed in	No. 2-D diesel fuel (or equivalent), selected for ambient temperature. Switch to a winter-grade blend in cold climates to prevent fuel waxing. Keep the tank full at the end of each shift to reduce condensation.

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

Komatsu 4D88E-3B(S/N 00101-UP) maintenance schedule

Service interval	Tasks
Every 10 h	Check engine oil level on the dipstick before starting; top off to the upper mark if low. Check coolant level in the reserve tank and radiator; add a 50/50 antifreeze mix if low. Drain water and sediment from the fuel strainer/water separator bowl. Inspect the block, filters, and hose connections for fresh oil, fuel, or coolant leaks. Check fan belt tension and condition weekly; replace if cracked or glazed. Clean or tap out the air cleaner element and empty the dust cup weekly.
Every 250 h	Change engine oil and replace the oil filter element. Replace the fuel filter element and bleed air from the fuel system. Check battery electrolyte level and clean and torque terminal connections. Inspect alternator and fan belt tension; adjust to factory spec. Clean the fuel water-separator bowl and confirm a secure seal.
Every 500 h	Replace the air cleaner element. Check and adjust intake and exhaust rocker arm (valve) clearance to factory spec. Inspect fuel injection nozzles for correct opening pressure and spray pattern; recondition as needed. Check coolant antifreeze concentration and top up corrosion inhibitor. Inspect the crankcase breather and clean if restricted. Check engine mounting bolts and vibration dampers for looseness or cracking.
Every 1,000 h	Check and adjust fuel injection pump timing. Inspect the water pump for shaft play, seal weep, or impeller wear. Inspect starter motor and alternator brushes for wear; clean commutator and slip rings. Retorque cylinder head bolts to factory sequence and spec. Inspect wiring harness and grounds near the battery and engine bay for chafing or corrosion.
Every 2,000 h	Drain and flush the cooling system completely; refill with fresh 50/50 antifreeze mix. Inspect camshaft gear and injection pump drive gear backlash. Measure and record cylinder compression on all cylinders for a wear-trend baseline. Recondition or replace injection nozzles as a set. Inspect the crankshaft pulley and vibration damper for wear or bonding failure.
Every 4,000 h	Pull the cylinder head for inspection; resurface or replace based on compression and oil-consumption trend. Inspect valve guides, seats, and stems for wear; replace valve seals as a set. Send the injection pump out for full calibration and internal inspection. Measure piston ring and cylinder bore wear against factory limits; recondition as needed.
Every 6,000 h	Remove and inspect crankshaft main and rod bearing clearances against factory limits. Measure camshaft lobe wear and bearing journal clearance. Inspect and recondition or replace the water pump assembly. Check governor flyweight and linkage wear if surging or hunting idle has shown up in service history.

Servicing the 4D88E-3B(S/N 00101-UP) beyond the schedule

Predictive Maintenance & Fluid Analysis

This dash-3 generation has no ECM and no stored fault codes — only oil-can, battery, and coolant-temperature warning lamps wired to mechanical switches. Predictive care means tracking trends by hand: pull an oil sample at every oil-filter change and watch for rising wear metals or silica, log glow-plug resistance and cranking speed, and record injection-nozzle pop-test pressures over time. Exhaust smoke color is a real diagnostic here — white points to air or a weak glow plug, blue to oil consumption, black to overfueling or a restricted air cleaner.

Corrective & Common Repairs

Cold-weather no-start on this block usually traces to weak glow plugs before the fuel system — check preheat timing and resistance first. Overheating shows up specifically under load, tracking or running hydraulics hard, most often from mud-packed radiator fins, a water-pump impeller that has corroded or slipped on its shaft, or a stuck thermostat; because the hydraulic oil cooler shares the same stack, a plugged cooler starves the water radiator too. Wiring harness chafing near the battery and frame causes intermittent shutdowns — inspect grounds and insulation before replacing components.

Overhaul & Rebuild Points

At major overhaul, measure cylinder bore and piston ring wear against factory limits and check crank-pin and main bearing clearances — this is a plain mechanical bottom end with no electronic wear-monitoring. Inspect camshaft lobe and gear backlash, since the camshaft drives both the valvetrain and the mechanical injection pump timing. Pop-test or recondition injection nozzles as a set rather than one at a time. Because the governor is a mechanical flyweight design, check weight and linkage wear if surging or hunting idle shows up in service history.

Seasonal & Environment Servicing

Switch engine oil from SAE 10W-30 to 5W-20 for cold-climate starting, and confirm glow-plug preheat timing before winter — this naturally aspirated block relies on preheat and compression alone with no turbo boost to help cold combustion. Hold coolant at a 50/50 antifreeze premix year-round for freeze protection, and switch to winter-grade diesel to prevent fuel waxing. On the compact chassis this engine fits, engine-bay clearance is tight — keep radiator and oil-cooler fins clear of mud and debris, and drain the fuel-water separator more often in wet climates.

4D88E-3B(S/N 00101-UP) common service parts

Part number	Part	Notes
(YM129100-55621)	Fuel Filter Ass'Y,(See Fig.A4110-B0a1)	Fuel system service	Check fitment →
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 →
YM121120-12901	Element	Scheduled service item	Check fitment →

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

4D88E-3B(S/N 00101-UP) fault codes & troubleshooting

Code	Meaning	Likely cause	What to do
Oil pressure warning lamp (oil can symbol, red)	Engine oil pressure has dropped below the switch threshold	Low oil level, worn oil pump, clogged oil strainer, or failed oil pressure switch	Stop engine immediately, check oil level and for leaks, verify oil pressure switch and wiring before restarting
Charge warning lamp (battery symbol, red)	Alternator is not charging the battery	Worn/slipping fan belt, faulty alternator, loose or corroded wiring connections	Check belt tension and alternator output; inspect wiring and battery terminals
Coolant temperature warning lamp (thermometer symbol, red)	Engine coolant temperature has exceeded the safe operating threshold	Low coolant level, clogged radiator, failed thermostat, or slipping/broken fan belt	Stop engine, let it cool, check coolant level and radiator fins/hoses before restarting

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

4D88E-3B(S/N 00101-UP) attachments & work tools

Machine type / host application

4D88E-3B is a power unit, not a complete machine, so no brand attachment guide covers it directly. It powers compact hydraulic excavators in the roughly 2-6 tonne class, plus mini skid-steer loaders and compact tracked carriers/dumpers from the same era and displacement class.

Application class range

Documented fitments span multiple carrier platforms rather than one machine line: compact excavators, mini skid-steer loaders, and tracked mini-dumper/carrier units all draw on the same 2.2 L four-cylinder block family. Exact carrier assignment for this specific 00101-UP serial range is not separately confirmed, so treat it as class-level coverage.

Combustion / aspiration configuration

The 4D88E-3B is a naturally aspirated, direct-injection, water-cooled inline four-cylinder diesel (88 mm bore x 90 mm stroke, 2.2 L). No turbocharged or intercooled factory option is documented for this suffix; forced induction shows up only on later 4D88E generations.

Cooling package

An engine-driven pusher-type cooling fan of roughly 440 mm diameter is the documented arrangement shared across 4D88E-3 series fitments. No separate remote-mount or hydraulic-drive cooling package is documented specifically for the 3B suffix.

Work-tool relevance (carrier-level, not engine-level)

Carrier machines built around this engine class (compact excavators, mini skid steers) run their own OEM work-tool programs sized to the 2-6 tonne class, e.g. general-purpose and ditching buckets, hydraulic breakers, and pin-grabber or manual quick couplers. These are attachments for the machine chassis and hydraulic circuit, not the engine itself, and no engine-specific mounting or coupler exists.

Suffix / variant family note

The 4D88E-3 family includes multiple suffix variants (3A, 3B, 3C, 3D, 3GB, 3H) tied to different original-equipment machine fitments. Public sources do not spell out a clear technical split between these suffixes, so any spec not explicitly tied to 3B should be treated as family-level, not confirmed for this exact variant.

All 4D88E-3B(S/N 00101-UP) assemblies by section

Every catalogued assembly group for the Komatsu 4D88E-3B(S/N 00101-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Engine

Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Air Cleaner And Mounting(#00145-)

YM***41	Buffle	1
YM***70	Seat,Rubber	2
YM***10	Cap	1
YM***30	Pan,Dust	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Air Intake Manifold And Connection

YM***01	Heater,Intake Air	1
YM***00	Manifold,Air Intake	1
YM***52	Bolt	9
YM***11	Gasket (Kit)	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Alternator (40a) (Inner Parts)(#00145-)

YM***50	Brush Ass'Y	1
YM***00	Retainer,Bearing	1
YM***70	Diode Ass'Y	1
YM***20	Nut Assembly., Pulley	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Alternator And Mounting (40a)(#00145-)

YM***30	Plate,Adjust	1
YM***02	Nut	1
YM***02	Nut	1
YM***00	Washer,Spring	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Camshaft And Tappet(#00145-)

YM***80	Camshaft Ass'Y	1
YM***01	Gear Ass'Y,Camshaft	1
YM***50	Bearing, Thrust	1
YM***62	Bolt,(For Shipping)	2

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Crankshaft(#00145-)

YM***00	Gear,Crank	1
YM***80	Parallel Pin	1
YM***50	Pulley,Crank	1
YM***10	Spring Pin	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Cylinder Block Accsessory(#00145-)

YM***00	O-Ring (Kit)	1
YM***50	Oil Pressure Transmitter	1
YM***20	Plug,Drain(Without Oil Cooler Type)	1
YM***52	Screw	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Cylinder Block(#00145-)

YM***30	Main Metal Ass'Y (Std)	5
YM***00	Plug	1
YM***50	Plug	1
YM***20	Screw	10

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Cylinder Head

YM***80	Retainer, Spring	8
YM***40	Seal,Valve? Exhaust (Kit)	4
YM***10	Valve,Exhaust	4
YM***10	Guide,Valve? Exhaust	4

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Cylinder Head Cover(#00145-)

YM***20	Cover, Breather	1
YM***51	Cap, Lub. Oil Supply	1
YM***90	Retainer	1
YM***70	Splash-Guard	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Drive Gear

YM***02	Nut	1
YM***01	Idler Gear Ass'Y,Idler	1
YM***00	Gear,Injection Pump	1
YM***52	Screw	2

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Electrical Parts (Forwerded Individually Parts)(#00145-)

YM***20	Timer,Solenoid	1
YM***10	Relay,Stop Solenoid	1
YM***00	Relay, Safety	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Exhaust Manifold(#00145-00938)

YM***10	Gasket (Kit)	1
YM***02	Stud	2
YM***02	Screw	6
YM***50	Nut	2

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Exhaust Manifold(#00939-)

YM***02	Screw	6
YM***00	Manifold, Exhaust	1
YM***10	Gasket (Kit)	1
YM***50	Nut	2

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Flywheel And Flywheel Housing(#00145-)

YM***02	Screw	6
YM***02	Screw	4
YM***90	Flywheel Ass'Y	1
YM***80	Parallel Pin	4

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Front Cover(#00145-)

YM***90	Front Cover Ass'Y	1
YM***51	Cap, Lub. Oil Supply	1
YM***00	Clip,Breather Hose	1
YM***52	Bolt	4

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Front Hanger(#00145-)

YM***00	Hook,Front	1
YM***42	Screw	2

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Fuel Filter And Water Separator Piping(#00145-)

YM***70	Union	1
YM***10	Hose,(See Fig.0415-17?0416-17)	1
YM***51	Check Valve Ass'Y,Joint	1
YM***40	Bolt,Pipe Joint	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Fuel Filter(#00145-)

YM***00	O-Ring (Kit)	1
YM***70	Lever	1
YM***80	Cup, Strainer	1
YM***50	Element,Fuel Filter	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Fuel Injection Pump (Governor) (1/2) (Inner Parts)(#00145-)

YM***40	Lever,Control	1
YM***30	Spacer,Lever Shaft	1
YM***02	Nut	1
YM***30	Solenoid,Engine Stop	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Fuel Injection Pump (Governor) (2/2) (Inner Parts)(#00145-)

YM***01	Weight Assembly., Governor	1
YM***50	Angleich Ass'Y	1
YM***00	Washer,Spring	1
YM***40	Link? L=30.5,L=30.5 (Mark 05)	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Fuel Injection Pump (Pump) (1/2) (Inner Parts)(#00145-)

YM***50	Kit, Shim	1
YM***10	Plate? Caution	1
YM***90	Key,Woodruff	1
YM***70	Injection Pump Ass'Y	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Fuel Injection Pump (Pump) (2/2) (Inner Parts)(#00145-)

YM***70	Retainer, Spring	4
YM***00	Rack,Control	1
YM***02	Screw	2
YM***00	Valve,Delivery	4

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Fuel Injection Pump And Piping(#00145-)

YM***20	Retainer, Pipe	2
YM***60	O-Ring,Fuel Injection Pump	1
YM***02	Nut	3
YM***20	Tube,Injection? No.2	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Fuel Nozzle And Spill Hose(#00145-)

YM***00	Nozzle, Assembly	1
YM***20	Spring	1
YM***00	Fuel Injection Nozzle, Assembly	1
YM***80	Pipe	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Gasket Kit(#00145-)

YM***60	O-Ring,Fuel Injection Pump	1
YM***40	Seal,Valve? Exhaust (Kit)	4
YM***20	Gasket,Water Pump	1
YM***00	O-Ring (Kit)	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Hydraulic Pump And Mounting(#00145-)

YM***20	Pump Ass'Y,Hydraulic	1
YM***02	Nut	2
YM***64	Bearing,Ball	2
YM***81	Gasket (Kit)	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Lubricating Oil Pump(#00145-)

YM***50	Pipe,Oil	1
YM***02	Seal,Ring (Kit)	2
YM***41	Gasket (Kit)	1
YM***20	Bolt,Joint (Cylinder Head Side)	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Muffler And Mounting(#00145-)

YM***22	Stud	4
YM***01	Gasket (Kit)	1
YM***02	Screw	4
YM***50	Stay	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Oil Filter

YM***50	Nut	1
YM***00	Valve,Relief	1
YM***02	Bolt Plated	3
YM***01	Support	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Oil Pan(#00145-)

YM***30	Spacer	1
YM***52	Screw	2
YM***52	Screw	24
YM***40	Plug,Drain	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Piston And Connecting Rod(#00145-)

YM***00	Screw	2
YM***00	Crank Pin Metal A. (Std)	1
YM***81	Piston Ass'Y	4
YM***50	Ring Set (+0.25 mm)	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Rear Hanger

YM***00	Hook,Front	1
YM***42	Screw	2

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Rocker Arm(#00145-)

YM***02	Nut,Rock	3
YM***02	Screw	7
YM***80	Spring	4
YM***50	Rocker Arm Ass'Y	8

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Starting Motor (Inner Parts)(#00145-)

YM***50	Pinion Ass'Y,Pinion	1
YM***20	Housing,Center	1
YM***40	Field Coil Ass'Y	1
YM***70	Brush Holder Ass'Y,Brush	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Starting Motor And Mounting(#00145-)

YM***52	Bolt Plated	2
YM***02	Nut,Rock	1
YM***00	Washer,Spring	1
(Y***1)	Starting Motor Ass'Y,(See Fig.A6210-B0a1)	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Water Pump And Cooling Fan(#00145-)

YM***60	Spacer	1
YM***20	Gasket,Water Pump	1
YM***30	Cover	1
YM***02	Screw	1

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Komatsu : 4d88e-3b(S/N 00101-Up) : Engine : Water Separator(#00145-)

YM***00	Gasket	2
YM***00	O-Ring (Kit)	1
YM***50	Plug,Air	2
YM***10	Bowl, Fuel Strainer	1

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4D88E-3B(S/N 00101-UP) serial number reference

This is a standalone engine model, not a complete machine, so there is no chassis-style PIN plate. The ID/data plate is riveted to the engine itself, typically on the block or rocker (cylinder head) cover near the fuel injection pump or flywheel housing side. Read the model code first (4D88E-3B), then the serial number that follows it: a plain numeric count starting at 00101 and up, not a 3-letter alpha prefix. Breakpoints inside the book (e.g. 00145-, 00939-) mark running production changes, not new model families, so match parts by both model code and exact serial number against the parts book breaks.

Prefix	Identifies	Notes
00101-UP	4D88E-3B engine, base serial block	Starting serial break for this engine's own parts book. Naturally aspirated, indirect-injection 4-cylinder diesel in the 88 mm bore family, third development series, sub-variant B, built on the Yanmar 4TNE88 base. Engine-only entity with no separate machine PIN; numbers from 00101 and up cover this whole parts book unless a later running-change break applies.
00145-UP	Running production change within the 4D88E-3B block	Mid-block breakpoint appearing across most engine sections (starting motor, alternator, cylinder block, camshaft, front cover, oil pan, fuel system, etc.), meaning parts before and after this point differ even though the engine stays in the same 00101-UP book. Not a separate engine model, just a later production change.
00939-UP	Later running change, exhaust manifold	Narrower breakpoint specific to the exhaust manifold group, splitting from an earlier 00145-00938 grouping. Same 4D88E-3B book, later change only affecting that one assembly.

Frequently asked questions

What engine does the Komatsu 4D88E-3B(S/N 00101-UP) use?

It is the engine, not a machine fitted with one. The 4D88E-3B is a vertical inline 4-cylinder, water-cooled, naturally aspirated diesel of 2.189 L (133.6 cu in) displacement with an 88 mm x 90 mm (3.46 in x 3.54 in) bore and stroke, built on the Yanmar 4TNE88 base block under license, with a mechanical direct-injection pump and flyweight governor rather than electronic controls.

What is the operating weight of the Komatsu 4D88E-3B(S/N 00101-UP)?

No operating weight applies — this is a standalone engine, not a complete machine, so that figure belongs to whatever chassis it is installed in. The base long block itself weighs approximately 170 kg (374 lb), typical for this engine platform before a radiator, alternator, starter, and other installed accessories are added; fitted weight varies by application.

What replaced the Komatsu 4D88E-3B(S/N 00101-UP)?

Within the Komatsu engine lineup, this mechanical dash-3 generation was succeeded by the electronically governed, EPA/Tier-certified 4D88E-5 and 4D88E-5X, then the 4D88E-6, and ultimately the Tier 4 Final 4D88E-7 with exhaust gas recirculation and a diesel particulate filter — same base block, with electronic control and emissions aftertreatment this earlier generation never carried.

What 4D88E-3B(S/N 00101-UP) owners discuss

What causes hard or no-start conditions in cold weather on machines with this engine?

On this small naturally aspirated block, slow cranking and no-start in cold weather usually trace back to weak glow plugs rather than the fuel system. It's common to find a glow plug not heating even on a machine that has always been a slow starter — check resistance and preheat timing (roughly 20-30 seconds) before chasing anything else. Air trapped in the fuel lines after a filter change, or a tired priming/lift section on the injection pump, is the next most reported cause; bleed the system fully after any fuel-side work. Corroded battery terminals or a poor engine-to-frame ground cut cranking speed further and mask the real fault, so clean and torque connections first.

What does exhaust smoke color tell you about this engine's condition?

Owners use smoke color as a first diagnostic. White smoke points to unburned fuel from air in the lines or a weak glow plug, and less often to coolant reaching a cylinder. Blue smoke means oil is being burned — worn rings, worn valve stem seals, or an overfull crankcase pushing oil past the breather. Black smoke under load usually means overfueling or a restricted air intake rather than a worn engine. A brief haze on cold start that clears within a few seconds of idle is normal; smoke that lingers or thickens under load is not.

What overheating pattern shows up on machines running this engine, and why?

The recurring complaint on the compact excavators and carriers this engine powers is overheating that appears specifically when tracking or working the hydraulics hard, not at idle. Reported causes, roughly in order of frequency: a radiator packed with mud or debris on the fin face (common given the tight engine bay and low ground clearance of these machines), a water pump whose internal impeller has corroded or slipped on its shaft so the belt turns the pump without moving coolant, and a stuck thermostat or failed temperature sender giving a false reading. Because the hydraulic oil cooler typically shares the same cooling stack as the radiator on these chassis, a plugged oil cooler can also starve airflow to the water radiator next to it. Flush and pressure-test the cooling system and confirm actual coolant flow with the thermostat pulled before condemning the radiator.

What electrical or wiring issues come up on machines with this engine?

Reported failures center on the wiring harness and grounds rather than engine controls — intermittent starting, a dead dash, or the machine shutting down at random while running, usually traced to a corroded ground strap or chafed harness insulation rubbing against the frame or floor plate. In one documented case, wiring disturbed near the battery during unrelated repair work developed a loose connection that overheated and smoked in use. Any harness that has been unbolted, rerouted, or shows chafing near sharp edges needs inspection for damaged insulation and secure, properly torqued terminals before the machine goes back to work. Have your dealer verify the battery cable and main harness routing if smoking, melted insulation, or a burning smell was ever reported.

What wear pattern shows up in the fuel injection pump and governor over time?

This engine uses a mechanical flyweight-type governor and a mechanical injection pump rather than electronic control, consistent with its era. Wear symptoms owners describe are a hunting or surging idle, gradual power loss under load with otherwise normal-looking smoke, and injectors drifting out of their opening pressure over time. Because the engine is naturally aspirated and modest in output to start with, a worn pump or tired injectors show up quickly as sluggish response rather than a fault code — there's no engine control module on this generation to flag it. Injector pop-testing and pump timing are periodic mechanical maintenance items, not a failure unique to this engine.

What undercarriage or wear pattern is typical on the host mini excavators built around this engine?

Not an engine issue, but a recurring complaint on these chassis: worn carrier rollers give a rough ride and let the track climb the roller edge and throw itself, and a worn idler guide or bracket lets the front idler wobble in the track frame and walk the track off under turning loads. Track tension that appears to loosen even without visible grease loss from the tensioner is usually roller or idler wear, not a tensioner leak. Worth checking on any used unit from this family regardless of exact engine suffix.

What should you check when buying a used machine fitted with this engine?

Start the engine cold and watch startup smoke — it should clear within a few seconds of idling; smoke that lingers or thickens under load points to ring or injector wear. Pull the dipstick and look for a milky or foamy sheen, which signals coolant crossing into the oil through the head gasket or oil cooler core, a known failure point on small oil-cooler-equipped diesels of this era. Confirm the glow plugs heat and that cold starts don't need starting fluid. Run the machine under load (tracking plus hydraulics together) for 20-30 minutes and watch coolant temperature, since that's when the reported overheating pattern shows up, not at idle. Check the wiring harness near the battery and engine bay for chafing, taped repairs, or heat discoloration. This engine variant is shared across several excavator and carrier chassis of its era, so confirm the engine and chassis serials match the listing rather than assuming compatibility from the model name alone.

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

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