Komatsu S6D170 Marine Engine Parts
The Komatsu S6D170 is a heavy-duty inline six-cylinder diesel engine from Komatsu’s 170-series engine family. In marine and marinized applications, engines from this family can be found in equipment where dependable operation, strong low-speed torque and long service life are important.
Unlike the turbocharged SA6D170 and turbocharged/aftercooled SAA6D170, the S6D170 is the naturally aspirated version of the family. This difference matters when identifying air-intake, exhaust and related engine components.
As these engines become older, maintenance requirements often move beyond normal filters and seals. An S6D170 that has accumulated significant operating hours may eventually require cylinder-head components, pistons, piston rings, bearings, cooling-system parts, lubrication-system components or a more extensive overhaul.
Alfa Marine Spare Parts supports Komatsu S6D170 Marine Engine Spare Parts requirements for:
- Routine Maintenance
- Fuel-System Repair
- Cooling-System Repair
- Lubrication-System Repair
- Cylinder Head Repair
- Air Intake and Exhaust Repair
- Internal Engine Repair
- Major Engine Overhaul
Depending on availability, supply options can include genuine Komatsu, OEM-quality, selected aftermarket and remanufactured components.
What Is the Komatsu S6D170 Engine?
The Komatsu S6D170 is a large-displacement, four-stroke, inline six-cylinder diesel engine.
Its basic construction includes major assemblies such as:
- Cylinder Block
- Cylinder Head and Valve Train
- Pistons
- Piston Rings
- Piston Pins
- Connecting Rods
- Crankshaft
- Main Bearings
- Connecting Rod Bearings
- Camshaft
- Timing Gear System
- Fuel Injection System
- Air Intake System
- Exhaust System
- Cooling System
- Lubrication System
- Starting System
- Charging System
Marine installations can also include additional equipment such as seawater pumps, heat exchangers and application-specific cooling or exhaust components.
Komatsu S6D170 Technical Information
The exact specifications and ratings can vary according to engine version and application. The engine identification plate and serial number should therefore be used when confirming application-specific specifications or replacement parts.
Technical InformationKomatsu S6D170ManufacturerKomatsuEngine Family170 SeriesEngine ModelS6D170Engine TypeHeavy-Duty DieselCylinder ArrangementInline 6-CylinderOperating CycleFour-StrokeBore170 mmStroke170 mmDisplacementApprox. 23.15 LitresAspirationNaturally AspiratedCoolingLiquid CooledLubricationPressure LubricationFuelDiesel
Rated output and operating speed should be confirmed against the exact S6D170 engine specification because ratings can vary by application.
What Does Komatsu S6D170 Mean?
The model designation identifies this engine within the wider Komatsu 170-series family.
Three closely related names are commonly encountered:
Komatsu S6D170
Komatsu SA6D170
Komatsu SAA6D170
They may look almost identical when written on a parts request, but the differences are important.
What Is the Difference Between S6D170, SA6D170 and SAA6D170?
In general, the major distinction concerns the engine's air-handling configuration:
S6D170 → Naturally Aspirated
SA6D170 → Turbocharged
SAA6D170 → Turbocharged with Charge-Air Cooling
The S6D170 does not use the turbocharger arrangement associated with the SA6D170.
This can affect:
- Air Intake Components
- Exhaust Components
- Manifolds
- Pipework
- Hoses
- Gaskets
- Cooling Components
- Mounting Hardware
This is one reason why simply requesting "Komatsu 170 engine parts" is not enough for many components.
The complete engine designation should be provided.
Does the Komatsu S6D170 Have a Turbocharger?
The S6D170 is naturally aspirated, so it should not be confused with the turbocharged SA6D170.
This distinction becomes particularly important when comparing parts lists between the S6D170, SA6D170 and SAA6D170.
If an engine identified as an S6D170 appears to have equipment inconsistent with the expected configuration, the engine identification plate and installed equipment should be checked carefully before ordering parts.
Komatsu S6D170 Air Intake Parts
Although the naturally aspirated S6D170 does not depend on a turbocharger, clean and unrestricted airflow remains essential for combustion.
Potential requirements can include:
- Air Filter Elements
- Air Cleaner Components
- Intake Pipes
- Intake Hoses
- Intake Connections
- Intake Manifold Components
- Clamps
- Gaskets
- Seals
Can a Dirty Air Filter Make an S6D170 Lose Power?
Yes.
A naturally aspirated diesel depends directly on atmospheric air entering the cylinders through the intake system.
If the air filter or intake path becomes restricted, the engine may receive less combustion air.
Possible symptoms can include:
- Reduced Engine Power
- Black Exhaust Smoke
- Poor Response Under Load
- Increased Fuel Consumption
- Higher Exhaust Temperature
Before moving directly into fuel-system repairs, the intake path should therefore be inspected.
Komatsu S6D170 Exhaust-System Parts
Potential requirements can include:
- Exhaust Manifold Components
- Exhaust Pipes
- Exhaust Connections
- Exhaust Gaskets
- Sealing Components
- Fasteners
- Associated Hardware
Why Should an S6D170 Exhaust Leak Be Investigated?
An exhaust leak can be more than an inconvenience in an engine room.
Possible signs include:
- Soot Around Exhaust Joints
- Abnormal Exhaust Noise
- Exhaust Gas Leakage
- Damaged Gaskets
- Loose or Damaged Fasteners
Exhaust leakage should be investigated rather than repeatedly cleaning away the soot.
The visible soot may simply be showing where the sealing problem is occurring.
Komatsu S6D170 Fuel-System Parts
The fuel system must deliver the correct amount of clean fuel consistently to all six cylinders.
Potential requirements can include:
- Fuel Injectors
- Injector Components
- Fuel Injection Components
- Fuel Transfer Components
- Primary Fuel Filters
- Secondary Fuel Filters
- Fuel-Water Separator Elements
- High-Pressure Fuel Pipes
- Fuel Return Components
- Injector Seals
- Fuel-System Gaskets
- O-Rings
What Happens When the S6D170 Fuel System Starts Losing Performance?
Possible symptoms can include:
- Difficult Starting
- Rough Running
- Uneven Cylinder Operation
- Increased Exhaust Smoke
- Reduced Engine Power
- Increased Fuel Consumption
- Poor Response Under Load
- Abnormal Combustion Noise
But these symptoms should not automatically be treated as proof of injector failure.
Poor compression, valve problems, restricted airflow or insufficient fuel supply can produce similar symptoms.
Komatsu S6D170 Fuel Injectors
Potential requirements can include:
- Complete Fuel Injectors
- Injector Components
- Injector Seals
- High-Pressure Fuel Pipes
- Fuel Return Components
- Associated Hardware
One S6D170 Cylinder Is Smoking — Does It Need an Injector?
Possibly, but the injector should not be the only component considered.
If one cylinder behaves differently from the other five, investigate:
- Injector Performance
- Fuel Delivery
- Cylinder Compression
- Intake Valve Condition
- Exhaust Valve Condition
- Valve Adjustment
- Piston Condition
- Piston Ring Condition
- Cylinder Condition
Cylinder-to-cylinder comparison can help identify whether the problem follows the fuel system or the mechanical condition of the cylinder.
Komatsu S6D170 Cooling-System Parts
Potential requirements can include:
- Cooling-Water Pump
- Water-Pump Components
- Thermostats
- Thermostat Housing Components
- Cooling Pipes
- Cooling Hoses
- Oil Cooler Components
- Gaskets
- O-Rings
- Seals
Why Can a Komatsu S6D170 Overheat?
Overheating is a symptom with several possible causes.
These can include:
- Low Coolant Level
- Poor Coolant Condition
- Thermostat Problems
- Reduced Cooling-Water Pump Performance
- Restricted Cooling Passages
- Oil Cooler Restriction
- Cooling-System Contamination
- Restricted Coolant Flow
For marine installations, the raw-water side also needs to be considered.
Why Does the S6D170 Run Hot Only When the Vessel Is Working Hard?
This can provide an important diagnostic clue.
At low load, the engine generates less heat.
As engine load increases, the cooling system must remove considerably more heat.
A cooling system that has gradually lost some of its capacity may therefore appear normal at light load but struggle during sustained heavy operation.
Possible areas to investigate include:
- Coolant Level
- Coolant Condition
- Thermostat
- Cooling-Water Pump
- Internal Cooling Passages
- Oil Cooler
- Cooling-System Restrictions
On a marine installation, also investigate the seawater side.
Komatsu S6D170 Cooling-Water Pump Parts
Potential requirements can include:
- Complete Cooling-Water Pump
- Pump Housing
- Pump Shaft
- Bearings
- Mechanical Seal
- Impeller
- Gaskets
- O-Rings
Does an S6D170 Water Pump Have to Leak Before It Has Failed?
No.
A pump can lose circulation performance without producing an obvious external coolant leak.
Possible internal problems can include:
- Bearing Wear
- Mechanical-Seal Deterioration
- Impeller Damage
- Internal Corrosion
- Cavitation
- Coolant Contamination
Cooling-system diagnosis should therefore look beyond visible leakage.
Komatsu S6D170 Marine Seawater Pump Parts
A marinized S6D170 may use a separate raw-water or seawater pump.
Potential requirements can include:
- Complete Seawater Pump
- Pump Housing
- Pump Shaft
- Bearings
- Mechanical Seal
- Impeller Where Applicable
- Wear Components
- Cover Components
- Gaskets
- O-Rings
Are All S6D170 Marine Seawater Pumps the Same?
Not necessarily.
The seawater pump can form part of the marine conversion rather than the standard base engine.
Different installations may therefore use different pump arrangements.
For identification, provide:
- Pump Manufacturer
- Pump Model
- Existing Part Number
- Engine Serial Number
- Clear Photographs
- Mounting Arrangement
- Pipe Connections
- Hose Connections
What Can Cause Low Seawater Flow?
Possible causes can include:
- Restricted Sea Strainer
- Blocked Seawater Intake
- Damaged Impeller Where Applicable
- Worn Seawater Pump
- Pump-Shaft Problems
- Restricted Raw-Water Pipework
- Heat Exchanger Restriction
- Debris in the Cooling Circuit
A reduction in raw-water flow may first become noticeable as rising engine temperature under sustained load.
Komatsu S6D170 Marine Heat Exchanger Parts
Depending on the marine installation, potential requirements can include:
- Complete Heat Exchanger
- Heat Exchanger Core
- Tube Bundle
- Housing
- End Covers
- Cooling Connections
- Gaskets
- O-Rings
- Seals
Why Can an S6D170 Heat Exchanger Gradually Lose Efficiency?
Marine heat exchangers operate in an environment where contamination and corrosion can gradually affect heat transfer.
Possible causes include:
- Salt Deposits
- Scale
- Sediment
- Marine Growth
- Corrosion Products
- Debris
- Restricted Seawater Flow
A partially restricted heat exchanger may still remove enough heat at low engine load but become insufficient as load increases.
Komatsu S6D170 Lubrication-System Parts
Potential requirements can include:
- Engine Oil Pump
- Oil Pump Components
- Engine Oil Filters
- Oil Cooler
- Oil Cooler Components
- Oil Pressure Components
- Oil Pipes
- Oil Lines
- Gaskets
- O-Rings
- Front Crankshaft Seal
- Rear Crankshaft Seal
Low Oil Pressure — Does the S6D170 Need a New Oil Pump?
Not automatically.
Possible causes can include:
- Low Oil Level
- Incorrect Lubricating Oil
- Deteriorated Oil
- Restricted Oil Filter
- Oil Pump Wear
- Pressure-Regulating Problems
- Excessive Main-Bearing Clearance
- Excessive Connecting Rod Bearing Clearance
- Internal Engine Wear
- Pressure Sender or Instrumentation Problems
This distinction becomes especially important on a high-hour engine.
If excessive bearing clearance is responsible for the pressure loss, replacing only the oil pump will not correct the underlying engine wear.
Komatsu S6D170 Oil Cooler Parts
Potential requirements can include:
- Complete Oil Cooler
- Oil Cooler Core
- Oil Cooler Housing
- Oil Connections
- Cooling Connections
- Gaskets
- O-Rings
- Seals
The oil cooler should be included when investigating abnormal lubricating-oil temperature or general cooling performance.
Komatsu S6D170 Cylinder Head Parts
Potential requirements can include:
- Cylinder Head Components
- Cylinder Head Gaskets
- Intake Valves
- Exhaust Valves
- Valve Guides
- Valve Seats
- Valve Springs
- Rocker Components
- Valve-Train Components
- Injector Sealing Components
- Valve Cover Gaskets
When Should S6D170 Cylinder Head Components Be Inspected?
Cylinder-head inspection may become necessary following:
- Engine Overheating
- Coolant Loss
- Head-Gasket Failure
- Low Compression
- Valve Problems
- Uneven Cylinder Performance
- Abnormal Combustion
- Major Engine Overhaul
Inspection should determine what can safely be reused, reconditioned or replaced.
What Should Be Checked During S6D170 Cylinder Head Inspection?
Important areas can include:
- Cracking
- Corrosion
- Flatness
- Sealing-Surface Condition
- Intake Valve Condition
- Exhaust Valve Condition
- Valve Seats
- Valve Guides
- Valve Springs
- Previous Machining
- Heat Damage
This is especially important when the engine has experienced serious overheating.
Komatsu S6D170 Cylinder Head Gaskets
When a cylinder-head gasket fails, replacing the gasket is only part of the repair.
The more important question is:
Why did the gasket fail?
Possible contributing conditions can include:
- Engine Overheating
- Cylinder Head Distortion
- Damaged Sealing Surfaces
- Cooling-System Problems
- Previous Assembly Problems
If the underlying cause remains, another gasket can fail.
Komatsu S6D170 Pistons and Piston Rings
Potential requirements can include:
- Complete Pistons
- Piston Ring Sets
- Piston Pins
- Piston Pin Bushings
- Retaining Components
Possible indications of piston, ring or cylinder wear can include:
- Excessive Blow-By
- Increased Oil Consumption
- Reduced Compression
- Difficult Starting
- Exhaust Smoke
- Reduced Engine Performance
Does Excessive Blow-By Mean the S6D170 Only Needs New Piston Rings?
Not necessarily.
Possible causes can include:
- Piston Ring Wear
- Cylinder Wear
- Piston Wear
- Ring-Groove Wear
- Internal Engine Damage
New piston rings cannot compensate for excessive cylinder or piston wear.
The components should be inspected and measured together.
Komatsu S6D170 Connecting Rod Parts
Potential requirements can include:
- Connecting Rods
- Connecting Rod Bearings
- Big-End Bearings
- Small-End Bushings
- Connecting Rod Bolts
- Associated Hardware
Connecting rods deserve careful inspection following:
- Bearing Failure
- Lubrication Failure
- Piston Damage
- Serious Internal Engine Damage
Komatsu S6D170 Crankshaft and Bearing Parts
Potential requirements can include:
- Complete Crankshaft
- Main Bearing Sets
- Connecting Rod Bearings
- Big-End Bearings
- Thrust Bearings
- Thrust Components
- Crankshaft Gear Components
- Front Crankshaft Seal
- Rear Crankshaft Seal
Why Should the S6D170 Crankshaft Be Measured Before Ordering Bearings?
Because an older S6D170 may already have been rebuilt.
The crankshaft may previously have been:
- Polished
- Repaired
- Reground
- Replaced
Inspection should consider:
- Main Journal Diameter
- Connecting Rod Journal Diameter
- Surface Condition
- Scoring
- Taper
- Out-of-Round Condition
- Heat Damage
- Previous Machining
If crankshaft dimensions have changed, the required bearings may also be different.
Measure first. Select bearings second.
Komatsu S6D170 Camshaft and Timing Parts
Potential requirements can include:
- Camshaft
- Camshaft Bearings
- Timing Gears
- Gear-Train Components
- Timing Covers
- Timing Cover Gaskets
- Valve-Train Components
- Related Bushings
During a major overhaul, these components should be inspected rather than automatically assumed to be reusable.
Komatsu S6D170 Gaskets and Seals
Potential requirements can include:
- Complete Engine Gasket Set
- Upper Gasket Set
- Lower Gasket Set
- Cylinder Head Gaskets
- Valve Cover Gaskets
- Intake Gaskets
- Exhaust Gaskets
- Oil Cooler Gaskets
- Cooling-System Gaskets
- Injector Seals
- O-Rings
- Front Crankshaft Seal
- Rear Crankshaft Seal
The correct gasket package should be matched to the exact S6D170 configuration.
Komatsu S6D170 Starter Motor and Alternator Parts
Electrical requirements can include:
- Starter Motor
- Starter Solenoid
- Starter Components
- Alternator
- Alternator Components
- Drive Belts
- Pulleys
- Belt-Tension Components
- Electrical Connections
For an older engine, identification from the component currently installed is useful because the starter motor or alternator may have been replaced previously.
Komatsu S6D170 Overhaul Parts
A planned S6D170 overhaul can require:
- Pistons
- Piston Rings
- Piston Pins
- Main Bearings
- Connecting Rod Bearings
- Thrust Components
- Connecting Rod Bushings
- Cylinder Head Components
- Intake Valves
- Exhaust Valves
- Crankshaft Seals
- Complete Gasket Set
- Engine Seal Kit
- Fuel-System Components
- Cooling-System Components
- Lubrication-System Components
Depending on inspection findings, additional requirements may include:
- Crankshaft
- Connecting Rods
- Camshaft
- Fuel Injectors
- Fuel Injection Components
- Cooling-Water Pump
- Oil Pump
- Oil Cooler
- Starter Motor
- Alternator
Should You Order an S6D170 Overhaul Kit Before Opening the Engine?
Some planned components can be prepared in advance, but the final overhaul parts list should ideally follow inspection and measurement.
Once the engine is disassembled, the workshop can determine:
Are the cylinders serviceable?
Can the pistons be reused?
Has the crankshaft previously been machined?
Which bearings are required?
What condition are the cylinder-head components in?
Are the connecting rods serviceable?
A practical sequence is:
Identify → Disassemble → Clean → Inspect → Measure → Confirm Parts → Rebuild
This helps prevent an overhaul from being built around assumptions.
What Information Should You Send for Komatsu S6D170 Parts?
For accurate Komatsu S6D170 Marine Engine Spare Parts identification, provide:
- Engine Model: Komatsu S6D170
- Complete Engine Variant
- Engine Serial Number
- Engine Identification Plate
- Existing Komatsu Part Number
- Component Manufacturer Number
- Part Description
- Quantity Required
- Clear Photographs
- Vessel or Equipment Application
- Delivery Country or Nearest Port
For fuel equipment, cooling pumps, seawater pumps, starter motors, alternators and marine conversion components, identification directly from the currently installed component is particularly useful.
Who Do We Supply?
Alfa Marine Spare Parts supports Komatsu S6D170 requirements for:
- Shipyards
- Ship Repairers
- Marine Engineers
- Chief Engineers
- Technical Superintendents
- Fleet Operators
- Marine Service Companies
- Commercial Fishing Companies
- Offshore Operators
- Government Fleets
- Maritime Contractors
- Boat Builders
- Marine Equipment Distributors
- Commercial Vessel Operators
Worldwide Komatsu S6D170 Marine Engine Parts Supply
Alfa Marine Spare Parts supports Komatsu S6D170 Marine Engine Spare Parts requirements across major marine markets, including Spain, Italy, Monaco, France, the Netherlands, Belgium, Germany, Greece, the United Kingdom, Dubai and the UAE, Nigeria, Miami and Florida, Texas, Toronto and Canada, the Caribbean, South America and other major international seaports.
Whether the requirement involves injectors, cooling-system components, cylinder-head parts, pistons, crankshaft bearings, gasket sets or a complete S6D170 overhaul package, correct identification remains the starting point.