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Cummins/Onan ISL Engine

Name: Cummins/Onan ISL Engine
Brand: Cummins/Onan

The Cummins/Onan ISL is a 6-cylinder turbocompresseur à géométrie variable (vg turbo) engine rated at 2100 rpm, producing up to 230 kW. It powers generator sets from Cummins/Onan, including the ISL 350, ISL 370 and ISL 400. It holds 27.6 L (7.3 gal) of oil.

Also known as: Cummins ISL

Part of the Cummins/Onan ISL engine family — 3 variants share parts & fitment.

Cylinders

2100 rpm

Rated speed

230 kW

Gross power

27.6 L

Oil capacity

On this pageSpecs Generator sets Maintenance FAQ Service intervals Torque & specs Fluids

Engine specifications

Oil capacity	27.6 L
Cylinders	6
Aspiration	Turbocompresseur à géométrie variable (VG Turbo)
Rated speed	2100 rpm
Gross power	230 kW

Generator sets powered by this engine

Cummins/Onan ISL 350Cummins/Onan ISL 370Cummins/Onan ISL 400

How to read your Cummins/Onan engine serial & model number →

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter			—
Fuel filter	32,187 miles / 50,000 km		—	1000 hr
Oil filter	20,000 miles / 32,187 km		—	500 hr
Battery	Not explicitly stated in the document		—
Belt			—	5000 hr
Coolant	About 240,000 miles (386,243 km) with standard antifreeze/coolant; up to 600,000 miles (965,607 km) with an ESI antifreeze such as Fleetguard Compleat; add one bottle of an extender product at the halfway mark		—
Coolant filter	None*		—
Oil	20,000 miles / 32,187 km	27.6 k	—	500 hr
Spark plug	150,000 miles / 5,000 hours / 48 months / 241,500 km		—	5000 hr

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

Item	Action	Hours	Months	Notes
Filtre à carburant primaire	Replace	500 hr	12 mo	20 000 milles (32 187 km)
Huile et filtre	Change	500 hr	12 mo	20 000 milles (32 187 km)
Oil & Filter	Change	500 hr	12 mo	20,000 miles / 32,187 km
Primary Fuel Filter	Change	500 hr	12 mo	20,000 miles / 32,187 km
Primary fuel filter	Replace	500 hr	12 mo	20,000 miles / 32,187 kilometers
Filtre à carburant secondaire	Replace	1000 hr	12 mo	30 000 milles (48 281 km)
Secondary Fuel Filter	Change	1000 hr	12 mo	40,000 miles / 64,374 km
Secondary Fuel Filter	Replace	1000 hr	12 mo	40,000 miles / 64,374 kilometers
Overhead adjustment	Adjust	5000 hr	48 mo	150,000 miles / 241,500 km
Réglage d'arbre à cames en tête	Adjust	5000 hr	48 mo	150 000 milles (241 402 km)
Long-life Coolant/Antifreeze	Change		72 mo	Long-life coolant/antifreeze formulas allow changes out to 600,000 miles (965,607 km) or 6 years
Std. coolant	Change		24 mo	240,000 miles / 386,243 km; N/A hours
Std. coolant change	Change		24 mo	Long-life coolant/antifreeze formulas allow changes out to six years
Vidange du liquide de refroidissement standard	Drain		24 mo	240 000 milles (386 243 km); heures = S/O

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

Type	Item	Value	Unit	Condition
Other	Advertised horsepower	230-260	kW
Other	Advertised horsepower	246-298	KW
Other	Advertised horsepower	250	hp	special rating for fire and RV applications
Other	Advertised horsepower	280	hp	special rating for fire and RV applications
Other	Advertised horsepower	300	hp
Other	Advertised horsepower	310	hp
Other	Advertised horsepower	310-350	hp
Other	Advertised horsepower	315	hp
Other	Advertised horsepower	330	hp
Other	Advertised horsepower	330-400	BHP
Other	Advertised horsepower	350	hp
Other	Advertised horsepower	370	hp
Other	Advertised horsepower	400	hp
Other	Advertised horsepower	450	hp
Other	Advertised horsepower	500	hp
Other	Advertised horsepower	525	hp
Other	Bore	4.49 in (114 mm)
Other	Certification	2001-CERTIFIED
Other	Couple d'embrayage	550	lb-pi
Other	Couple d'embrayage	745	N·m
Other	Dry weight	1,555	lb
Other	Dry weight	705	kg
Other	Net weight	1,555	LB
Other	Net weight	705	KG
Other	Oil Capacity	7.3 U.S. gallons (27.6 liters)
Other	Oil system capacity	27.6	liters
Other	Oil system capacity	7.3	U.S. GALLONS
Other	Peak torque	1424-1695	N·M
Other	Stroke	5.69 in (144.5 mm)
Other	Weight (Dry)	1,555 lb (706 kg)
Speed	Governed Speed	2200	RPM
Speed	Governed speed	2000	RPM
Speed	Governed speed	2100	RPM
Speed	Governed speed	2100-2200	rpm
Speed	Governed speed	2600	RPM
Speed	Governed speed	2800	RPM
Torque	Clutch Engagement Torque	550	lb-ft
Torque	Clutch Engagement Torque	745	N·m
Torque	Clutch Engagement Torque	746	N•M
Torque	Peak Torque	1050	lb-ft
Torque	Peak Torque	1424	N·m
Torque	Peak Torque	1627	N•M
Torque	Peak torque	1050-1250	lb-ft
Torque	Peak torque	1100	lb-ft	@ 1300 RPM; special rating for fire and RV applications
Torque	Peak torque	1150	lb-ft	@ 1300 RPM
Torque	Peak torque	1200	LB-FT	at 1300 rpm
Torque	Peak torque	1423-1694	N-m
Torque	Peak torque	1450		at 1300 RPM
Torque	Peak torque	1550		at 1200 RPM
Torque	Peak torque	1650		at 1200 RPM
Torque	Peak torque	600		at 1600 RPM
Torque	Peak torque	660		at 1600 RPM
Torque	Peak torque	730	lb-ft	@ 1300 RPM; special rating for fire and RV applications
Torque	Peak torque	900	lb-ft	@ 1300 RPM; special rating for fire and RV applications
Torque	Peak torque	950		at 1400 RPM

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

Fluid	Grade	Standard	Notes
Coolant		long-life coolant/antifreeze formulas	Fully compatible with long-life coolant/antifreeze formulas which allow changes out to 600,000 miles (965,607 km) or 6 years. Follow maintenance guidelines recommended by the manufacturer for safe use with extended service intervals.
Coolant	Extended Service Interval (ESI) antifreeze	Fleetguard Compleat	Standard antifreeze/coolant needs replacing at about 240,000 miles (386,243 km); ESI antifreeze such as Fleetguard Compleat goes up to 600,000 miles (965,607 km) if one bottle of an extender product is added at the halfway mark
Fuel	No. 2 diesel

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

Common questions

What is the oil capacity of the Cummins/Onan ISL?

The Cummins/Onan ISL engine has an oil capacity of 27.6 liters.

Which generators use the Cummins/Onan ISL engine?

The Cummins/Onan ISL powers 3 generator set(s), including Cummins/Onan ISL 350, Cummins/Onan ISL 370, Cummins/Onan ISL 400.

How often should you change the oil in the Cummins/Onan ISL?

The Cummins/Onan ISL oil change interval is every 500 hours.