HomeEnginesIn-line 4 cyl.

In-line 4 cyl. Engine

The In-line 4 cyl. is a 4-cylinder engine rated at 1800 rpm. It powers generator sets from Generac, including the Guardian Series 25 kW, Guardian Series 30 kW, Guardian Series 45 kW and Guardian Series 60 kW.

Also known as: In-line 4 cyl.

4
Cylinders
1800 rpm
Rated speed

Engine specifications

Cylinders4
Rated speed1800 rpm

Common problems

15
  • Warning active. SERVICE SCHEDULE C
    Fix: Perform SERVICE SCHEDULE C maintenance; press ENTER to clear.
  • Warning active. SERVICE SCHEDULE B
    Fix: Perform SERVICE SCHEDULE B maintenance; press ENTER to clear.
  • Warning active. SERVICE SCHEDULE A
    Fix: Perform SERVICE SCHEDULE A maintenance; press ENTER to clear.
  • Warning active. LOW BATTERY
    Fix: Clear alarm. From the MAIN menu on the control panel, navigate to the BATTERY MENU. Contact servicing dealer if battery is GOOD. Replace battery If CHECK BATTERY is displayed.
  • Warning active. CHARGER WARNING
    Fix: Contact servicing dealer.
  • Warning active. BATTERY PROBLEM
    Fix: Contact servicing dealer.
  • Unit will not start in AUTO with utility loss. UNDERVOLTAGE
    Fix: Contact servicing dealer.
  • Unit will not start in AUTO with utility loss. UNDERSPEED
    Fix: Contact servicing dealer.
  • Unit will not start in AUTO with utility loss. RPM SENSE LOSS
    Fix: Clear alarm. From the MAIN menu on the control panel, navigate to the BATTERY MENU. Contact servicing dealer if battery is GOOD. Replace battery If CHECK BATTERY is displayed.
  • Unit will not start in AUTO with utility loss. OVERVOLTAGE
    Fix: Contact servicing dealer.
  • Unit will not start in AUTO with utility loss. OVERSPEED
    Fix: Contact servicing dealer.
  • Unit will not start in AUTO with utility loss. OVERCRANK
    Fix: Clear alarm. Attempt to start the unit in MANUAL. If it does not start or starts and runs rough, contact servicing dealer.
  • Unit will not start in AUTO with utility loss. NOT ACTIVATED
    Fix: Refer to activation section in Owner’s Manual.
  • Unit will not start in AUTO with utility loss. MISWIRE
    Fix: Contact servicing dealer.
  • Unit will not start in AUTO with utility loss. LOW OIL PRESSURE
    Fix: Check oil level. Add oil per Owner’s Manual. Contact servicing dealer if oil level is correct.

Compiled from service & troubleshooting documentation across every generator set that uses the In-line 4 cyl..

Service intervals

6
ItemActionHoursMonthsNotes
Replace fuel filterReplace500 hr
Replace oil and filterChange500 hr
Drain/flush coolant systemDrain1000 hr
Check coolant level and hosesCheckFirst service
Check fuel levelCheckFirst service
Check oil levelCheckFirst service

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

4
TypeItemValueUnitCondition
OtherTotal Harmonic Distortion<5%
SpeedSteady State Regulation (Governor)±0.25%
TorqueOperating temperature rise120°C above 40°C ambientrated output
VoltageVoltage Regulation±1%

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
CoolantPeak Fleet-Charge 50/50 ethylene glycol-20°C to 48°C2.8 galUse demineralized or distilled water base
Engine oilSAE rated high detergent oilAPI Service Class SFfor gasoline engines, similar to your car; refer to owner's manual for details
Engine oil15W-40API Service Class CD or better-20°C to 48°CSynthetic oil can be used in appropriate weight
FuelUltra Low Sulfur Dieselbelow 40°CMechanical engine-driven pump, 5 micron filter (15/20/30 kW), 10 micron filter (48/50 kW)

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

Fault codes

6
CodeNameMeaningSeverityAction
HIGH TEMPERATUREHigh TemperatureEngine coolant temperature exceeds limitShutdown
LOW OIL PRESSURELow Oil PressureOil pressure below acceptable levelWarning
NOT ACTIVATEDNot ActivatedUnit will not start in AUTO with utility lossInfo
OVERCRANKOvercrankEngine overcrank faultWarning
OVERLOADOverloadUnit overloaded, shuts down during operationShutdown
RPM SENSE LOSSRPM Sense LossLoss of engine RPM signalShutdown

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

Voltage reconnection

VoltagePhaseConnectionLeadsNotes
120/2083Three phaseRD015, RD020, RD030, RD050
120/2401Single phaseRD015, RD020, RD030, RD048
120/2403Three phaseRD015, RD020, RD030, RD048, RD050
277/4803Three phaseRD030, RD048, RD050

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

Which generators use the In-line 4 cyl. engine?

The In-line 4 cyl. powers 9 generator set(s), including Generac Guardian Series 25 kW, Generac Guardian Series 30 kW, Generac Guardian Series 45 kW, Generac Guardian Series 60 kW, Generac RD015.

What is a common problem with the In-line 4 cyl. engine?

A commonly reported issue on generators using the In-line 4 cyl. is: Warning active. SERVICE SCHEDULE C. Fix: Perform SERVICE SCHEDULE C maintenance; press ENTER to clear..