The Cummins/Onan QSK23-G7 is a 23 L 6-cylinder turbocharged and low temperature after-cooled engine rated at 1800 rpm. It powers generator sets from Cummins/Onan, including the C1600D6RG, C800D6RG and QSK23. It holds 102 L (26.9 gal) of oil.
Also known as: Cummins QSK23-G7
Part of the Cummins/Onan QSK23 engine family — 10 variants share parts & fitment.
| Oil capacity | 102.0 L |
|---|---|
| Displacement | 23.0 L |
| Cylinders | 6 |
| Aspiration | turbocharged and low temperature after-cooled |
| Rated speed | 1800 rpm |
How to read your Cummins/Onan engine serial & model number →
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | — | ||||
| Fuel filter | — | ||||
| Oil filter | — | ||||
| Battery | — | ||||
| Belt | — | ||||
| Coolant | — | ||||
| Oil | — | ||||
| Spark plug | — |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
| Item | Action | Hours | Months | Notes |
|---|---|---|---|---|
| Lubricating oil | Test | 250 hr | 6 mo | First 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. |
| filters | Change | 1000 hr | with CENTINEL, depending on load factors | |
| ELIMINATOR self cleaning filter core | Other | 1500 hr | Requires servicing only every 1,500 hours. Saves up to 90% of lube system maintenance costs and increases productivity. | |
| fuel filter | Change | 1500 hr | Fleetguard NanoNet media | |
| valve clearance | Check | 2000 hr | B-Series (4BT3.3): valve clearance checks not required for 2000 hours, twice the industry standard | |
| engine oil | Change | 4500 hr | with CENTINEL, railway applications | |
| engine overhaul | Other | 20000 hr | QSK23-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.
| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Other | DB9F-DB9M serial cable length (Part Number 4918418) | 1.83 | M | |
| Other | Extension DB9F to DB9M length (Part Number 3162851) | 30.48 | M | |
| Other | INLINE™5 datalink adapter current requirement | 250 | mA | at +8 VDC to +50 VDC |
| Other | USB cable length (Part Number 4918419) | 2 | M | |
| Other | USB cable length (Part Number 4918591) | 5 | M | |
| Voltage | INLINE™5 datalink adapter supply voltage (maximum) | +50 | VDC | power lamp fast flashing indicates greater than maximum |
| Voltage | INLINE™5 datalink adapter supply voltage (minimum) | +8 | VDC | power 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.
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|---|---|---|---|---|
| Engine oil | Cummins Engine Oil Recommendations Bulletin 3810340 | Used to analyze oil samples for high horsepower engines with Eliminator™ oil filter option. | |||
| Fuel | B100 biodiesel | ASTM D6751 | Must conform prior to blending; revised to include a cold soak test; stability requirement still in effect. | ||
| Fuel | B20 biodiesel blend | ASTM D7467 | Applies 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. | ||
| Fuel | B5 biodiesel | All Cummins automotive and industrial engines are compatible with B5 biodiesel. | |||
| Fuel | biodiesel (Europe) | EN 14214 | Published 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.
⚠ A fully populated USB cable, Part Number 4918419, or DB9F-DB9M serial cable, Part Number 4918418, must be used.
⚠ B20 has a solvent nature and may clean the vehicle fuel tank and lines.
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Part # | Description | Category |
|---|---|---|
| AF2559300 | Air Cleaner replacement element (Nelson), for Air Cleaner Housing 140-3737 | Air filter |
| 501-0876 | Line, Fuel Cooler Return (Bearward Cooling System, not shown) | Hose |
| 501-0877 | Line, Fuel Supply (Engine Accessories group) | Hose |
| 501-0892 | Line, Fuel Cooler Supply (Bearward Cooling System, not shown) | Hose |
| 503-1675 | Hose, Reducer (Air Cleaner group) | Hose |
| 503-2754-01 | Hose, Oil | Hose |
| A053A190 | Hose, Oil (Valve group) | Hose |
| 140-1548 | Indicator, Service | Service part / kit |
| 204-009 | Acronyms and Abbreviations | Service part / kit |
| 3822735 | Plastic bead blasting media | Service part / kit |
| 4021375 | QSK23 Troubleshooting and Repair Manual | Service part / kit |
| DKE1200BHT | Litho in U.S.A. (17-10) | Service part / kit |
| EX1200-7 | Upperstructure (continued) | Service part / kit |
| KS-E368R | Head Office | Service part / kit |
| A059Z452 | Seal, O Ring (Valve group) | Seal |
| A055E534 | Switch, 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.
The Cummins/Onan QSK23-G7 engine has an oil capacity of 102.0 liters.
The Cummins/Onan QSK23-G7 has a displacement of 23.0 liters with 6 cylinders.
The Cummins/Onan QSK23-G7 powers 3 generator set(s), including Cummins/Onan C1600D6RG, Cummins/Onan C800D6RG, Cummins/Onan QSK23.