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Cummins/Onan QSK23-G2 Engine

The Cummins/Onan QSK23-G2 is a 23 L engine rated at 1500 rpm. It powers generator sets from Cummins/Onan, including the QSK23.

Also known as: Cummins QSK23-G2

Part of the Cummins/Onan QSK23 engine family — 10 variants share parts & fitment.

23.0 L
Displacement
1500 rpm
Rated speed

Engine specifications

Displacement23.0 L
Rated speed1500 rpm

Service intervals

7
ItemActionHoursMonthsNotes
Lubricating oilTest250 hr6 moFirst service — For high horsepower engines with Eliminator™ oil filter option: take oil samples every 250 hours and analyze per Cummins Engine Oil Recommendations Bulletin 3810340; repeat for at least three oil change intervals.
filtersChange1000 hrwith CENTINEL, depending on load factors
ELIMINATOR self cleaning filter coreOther1500 hrRequires servicing only every 1,500 hours. Saves up to 90% of lube system maintenance costs and increases productivity.
fuel filterChange1500 hrFleetguard NanoNet media
valve clearanceCheck2000 hrB-Series (4BT3.3): valve clearance checks not required for 2000 hours, twice the industry standard
engine oilChange4500 hrwith CENTINEL, railway applications
engine overhaulOther20000 hrQSK23-Series: expected life cycle to 20,000 hours before first overhaul

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

7
TypeItemValueUnitCondition
OtherDB9F-DB9M serial cable length (Part Number 4918418)1.83M
OtherExtension DB9F to DB9M length (Part Number 3162851)30.48M
OtherINLINE™5 datalink adapter current requirement250mAat +8 VDC to +50 VDC
OtherUSB cable length (Part Number 4918419)2M
OtherUSB cable length (Part Number 4918591)5M
VoltageINLINE™5 datalink adapter supply voltage (maximum)+50VDCpower lamp fast flashing indicates greater than maximum
VoltageINLINE™5 datalink adapter supply voltage (minimum)+8VDCpower lamp slow flashing indicates less than minimum

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

FluidGradeStandardAmbientCapacityNotes
Engine oilCummins Engine Oil Recommendations Bulletin 3810340Used to analyze oil samples for high horsepower engines with Eliminator™ oil filter option.
FuelB100 biodieselASTM D6751Must conform prior to blending; revised to include a cold soak test; stability requirement still in effect.
FuelB20 biodiesel blendASTM D7467Applies to biodiesel blends B6–B20; includes oxidation stability requirement; replaces Cummins' previous EMA B20 specification requirement. Must be purchased from a BQ9000 Certified Marketer; B100 must be sourced from a BQ9000 Accredited Producer.
FuelB5 biodieselAll Cummins automotive and industrial engines are compatible with B5 biodiesel.
Fuelbiodiesel (Europe)EN 14214Published by CEN, European Committee for Standardization. Equivalent biodiesel specifications required internationally.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

3
Connect the INLINE™5 Datalink Adapter to a Personal Computer installation

⚠ A fully populated USB cable, Part Number 4918419, or DB9F-DB9M serial cable, Part Number 4918418, must be used.

  1. Connect the DB9F-DB9M serial cable, Part Number 4918418, or USB cable, Part Number 4918419, to the computer.
  2. Connect the other end of that cable to the INLINE™5 datalink adapter, Part Number 3165033.
  3. Supply +8 VDC to +50 VDC at 250mA through the OEM connector or a separate power source.
  4. Connect the appropriate datalink cable to the INLINE™5 datalink adapter, Part Number 3165033.
  5. Connect the other end of the datalink cable to the vehicle cab or engine compartment datalink connector.
  6. Launch the electronic service tool application software.
Oil sampling for high horsepower engines with Eliminator™ oil filter option maintenance
  1. Take oil samples every 250 hours of operation.
  2. Analyze samples according to Cummins Engine Oil Recommendations Bulletin 3810340.
  3. Repeat for at least three oil change intervals to ensure consistent oil behavior.
Switching from petrodiesel to B20 on used engines maintenance

⚠ B20 has a solvent nature and may clean the vehicle fuel tank and lines.

  1. Install new fuel filters when switching to B20.
  2. Replace fuel filters at half the standard interval for the next two fuel filter changes.
  3. After the initial period, revert to intervals specified in the O & M manual.
  4. For EPA 2007 on-highway midrange engines, sample oil for the first 6 months to monitor fuel dilution.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Parts cataloged across the Cummins/Onan QSK23 family

16
Part #DescriptionCategory
AF2559300Air Cleaner replacement element (Nelson), for Air Cleaner Housing 140-3737Air filter
501-0876Line, Fuel Cooler Return (Bearward Cooling System, not shown)Hose
501-0877Line, Fuel Supply (Engine Accessories group)Hose
501-0892Line, Fuel Cooler Supply (Bearward Cooling System, not shown)Hose
503-1675Hose, Reducer (Air Cleaner group)Hose
503-2754-01Hose, OilHose
A053A190Hose, Oil (Valve group)Hose
140-1548Indicator, ServiceService part / kit
204-009Acronyms and AbbreviationsService part / kit
3822735Plastic bead blasting mediaService part / kit
4021375QSK23 Troubleshooting and Repair ManualService part / kit
DKE1200BHTLitho in U.S.A. (17-10)Service part / kit
EX1200-7Upperstructure (continued)Service part / kit
KS-E368RHead OfficeService part / kit
A059Z452Seal, O Ring (Valve group)Seal
A055E534Switch, Level (low coolant level warning)Sensor

Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.

Common questions

What is the displacement of the Cummins/Onan QSK23-G2?

The Cummins/Onan QSK23-G2 has a displacement of 23.0 liters.

Which generators use the Cummins/Onan QSK23-G2 engine?

The Cummins/Onan QSK23-G2 powers 1 generator set(s), including Cummins/Onan QSK23.