HomeEnginesCummins/Onan KT19

Cummins/Onan KT19 Engine

The Cummins/Onan KT19 is a 18.7 L engine. It powers generator sets from AKSA and Cummins/Onan, including the AC500, AC550 and Kt19.

Also known as: CUMMINS KT19

Part of the Cummins/Onan KT19 engine family — 2 variants share parts & fitment.

18.7 L
Displacement

Engine specifications

Displacement18.7 L

Generator sets powered by this engine

3

Shared across brands: AKSA, Cummins/Onan

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

Common problems

14
  • White Smoke or Rough Running At Idle (After Warmup Period)
    Cause: Low Coolant Temperature
    Fix: Refer to “Coolant Temperature Below Normal” chart.
  • Radiator Shutters are not Opening Completely or Cold Weather Radiator Cover Closed
    Fix: Inspect the shutters. Repair or replace if necessary. Open radiator cover.
  • Lubricating Oil Pressure Low
    Cause: Incorrect Oil Level
    Fix: Check for oil leaks. Add or drain engine oil. Check dipstick calibration.
  • Exhaust Smoke Excessive Under Load
    Cause: Intake Air System Restricted; Intake Air Leaks Between Turbo-charger and Cylinder Head; Fuel Specifications Wrong; Valves or Injector Adjusted Wrong
    Fix: Check intake air system for restrictions.; Check for air leaks.; Check fuel specifications.; Check/adjust valves or injectors.
  • Engine Will Not Shut Off
    Cause: Fuel Pump Manual Override Open.
    Fix: Check to make sure manual override screw is out to maximum travel.
  • Engine Will Not Reach Rated Speed When Loaded
    Cause: Excessive Load for Engine Horsepower Rating; Tachometer Has a Malfunction; Throttle Linkage Adjustment Wrong; Fuel Suction Line Restricted
    Fix: Reduce vehicle load or use lower gear.; Check with hand or digital tachometer.; Check for full throttle travel.; Check fuel inlet for restriction.
  • Engine Will Not Crank or Cranks Slowly (Electric Starter)
    Cause: Incorrect Oil
    Fix: Change oil and filters. Use recommended type (15W-40).
  • Engine Will Not Crank or Cranks Slowly (Air Starter)
    Cause: Incorrect Oil For Operating Conditions
    Fix: Change oil and filters. Use recommended type (15W-40).
  • Engine Starts But Will Not Keep Running
    Cause: Air In The Fuel System
    Fix: Check for air in fuel, tighten fuel connections, tighten filter, check fuel tank stand pipe.
  • Engine Power Output Low
    Cause: Excessive Load for Engine Horsepower Rating; Low Power Due to Altitude; Fuel Suction Line or Fuel Filter Restricted; Lubricating Oil Level Too High; Throttle Linkage Adjustment Wrong; Intake or Exhaust System Restricted; Air in Fuel - Spongy Throttle; Fuel Drain Line Restricted or Fuel Tank Vents Plugged
    Fix: Reduce vehicle load.; Derate engine above 3600 meters altitude.; Check fuel line for restriction. Replace fuel filter.; Check dipstick calibration and off pan capacity.; Check throttie linkage adjustment for full opening of throttle lever.; Check intake and exhaust systems for restrictions.; Check for air in fuet, tighten fuel connections and filter, check fuel tank stand pipe.; Check fuel drain line for toops, crimps or clamped points. Remove, clean, or replace venis.
  • Engine Hard to Start or Will Not Start (Exhaust Smoke Present)
    Cause: Engine Cranking Speed Low (Below 150 RPM)
    Fix: Check engine starting system.
  • Engine Cranks But Will Not Start (No Smoke From Exhaust)
    Cause: No Fuel In Tank
    Fix: Add fuel.
  • Coolant Temperature Below Normal
    Cause: Radiator Shutters Stuck in Open Position or Opening Early
    Fix: Inspect the shutters. Repair or replace if necessary.
  • Coolant Temperature Above Normal
    Cause: Low Coolant Level; Air Trapped in Cooling System; Plugged Heat Exchanger; Plugged Cooling Passages in Cylinder Head, Head Gasket, or Cylinder Block; Malfunctioning Keel Cooler
    Fix: Add coolant.; Vent the cooling system to remove air.; Check/replace heat exchanger.; Flush the cooling system; fill with new coolant.; Refer to vessel manufacturer's service instructions.

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan KT19.

Maintenance schedule

ItemSpecCapacityPart #Interval
Air filterFan Idler Pulley Assembly1400606000 hr Amazon eBay
Fuel filterTurbocharger3810313-006000 hr Amazon eBay
Oil filterWater Pump33750496000 hr Amazon eBay
Battery1500 hr
BeltCheck belt tension in the center span of the pulleys using a Drive Belt Tension Chart.1500 hr
Coolant filter3810263-006000 hr Amazon eBay $150.00
Oil38.0 l1500 hr
Spark plug6000 hr

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

Parts cataloged across the Cummins/Onan KT19 family

149
Part #DescriptionCategory
140060Fan Hub (Gear Driven)air_filter
256837Air Compressor Air Cleaner Element - Two-Cylinder, Sponge Elementair_filter
45 083 01-SPrecleanerair_filter
45 083 02-SAir Filterair_filter
45 883 02-S1Air Filter/Precleanerair_filter
47 083 01-SAir Filterair_filter
47 883 01-S1Air Filter/Precleanerair_filter
52 083 01-SPrecleanerair_filter
3377193Battery Testerbattery_tester
3823138Belt Tension Gauge (Poly V-belt)belt_tension_gauge
25 050 07-SFuel Filter 75 Micronsfuel_filter
FS1212Fuel/Water Sep Spin-Onfuel_filter
FS1242Fuel/Water Sep Spin-Onfuel_filter
FP-IFKKT19KT19 In-Frame Kit w/upper gasket set & oil pan gasketgasket
M-206576Turbine Inlet Mounting Gasketgasket
M-3177942Turbine Inlet Mounting Gasket Low Pressuregasket
M-4352576Upper Gasket Setgasket
M-205243Impeller Cast Ironimpeller
3810313-00PT (Type D) STC Injector Shop Manualinjector
3822575Injector and valve adjustment kitinjector
M-3016825Roller - Injector Leverinjector
M-3062141Roller - Injector Lever Widerinjector
M-4009247Pin - Injector Leverinjector
3376000Injector pullerinjector_puller
3376497Injector pullerinjector_puller
3379084PT Fuel Pump Rebuild and Calibrate Manual, Bulletin No. 3379084manual
193736O-ring (3), Part No. 193736, has a green dot or stripe.o_ring
205216O-ring (2), Part No. 205216, has no markings.o_ring
3010510O-ring (1), Part No. 3010510, has a red dot or stripe.o_ring
3375049Oil Filter Wrenchoil_filter
25 755 05-SSolenoid Repair Kitother_service
25 755 06-SSolenoid Repair Kitother_service
25 757 02-SCarburetor Repair Kitother_service
25 757 03-SFloat Repair Kitother_service
25 757 09-SFloat Repair Kitother_service
25 757 11-SCarburetor Repair Kitother_service
3007525Liner Kit STDother_service
3012611Liner Kit +.010" UPFother_service
3012612Liner Kit +.020" UPFother_service
3022157Cylinder Liner STDother_service
3023017Cylinder Liner +.010" UPFother_service
3023018Cylinder Liner +.020" UPFother_service
3023019Cylinder Liner +.030" UPFother_service
3023020Cylinder Liner +.040" UPFother_service
3096680Piston STC 13.8:1 Ratioother_service
3096681Piston KT Series 15.5:1 Ratioother_service
3096682Piston KTA Series 14.5:1 Ratioother_service
3096683Piston 13.5:1 Ratioother_service
3096684Piston KTA 15.7:1 Ratioother_service
3096685Piston STC 13.9:1 Ratioother_service
3376592Inch Pound Torque Wrenchother_service
3628731Piston STC Kitother_service
3630913Piston KTA-50-G7other_service
3631241Piston Kit STC 13.9:1 Ratioother_service
3631242Piston Kit 13.5:1 Ratioother_service
3631243Piston Kit KTA 15.7:1 Ratioother_service
3631244Piston Kit KTA Series 14.5:1 Ratioother_service
3631245Piston Kit KT Series 15.5:1 Ratioother_service
3631246Piston Kit STC 13.8:1 Ratioother_service
3801268Liner Kit +.030" UPFother_service
3801269Liner Kit +.040" UPFother_service
3803530Piston Assembly STCother_service
3804747Piston Kit KTA-50-G7other_service
3804885Piston KTA-50-G8/G9other_service
3822574Rocker lever actuatorother_service
3822648/3823348Top Stop Tappet Setting Tool (STC equipped engines only)other_service
4009220Cylinder Liner QSK19/KT19 STDother_service
4009221Cylinder Liner +.020" UPFother_service
4009222Cylinder Liner +.040" UPFother_service
4009227Cylinder Liner KT19 Block Type #2other_service
4009233Cylinder Liner +.060" UPFother_service
4024767Cylinder Liner Kit QSK19/KT19 STDother_service
4024768Cylinder Liner Kit +.020" UPFother_service
4024769Cylinder Liner Kit +.040" UPFother_service
4024770Cylinder Liner Kit KT19 Block Type #2other_service
4024775Cylinder Liner Kit +.060" UPFother_service
4089847Piston Kit GTA38/19other_service
4090013Piston Kit KTA-38-M2other_service
4090029Piston Kit QSK19CEother_service
4090181Piston GTA38/19other_service
4097889Piston KTA-38-M2other_service
4333987Cylinder Liner +.020" / +.020"other_service
4333988Cylinder Liner +.060" / +.020"other_service
4333989Cylinder Liner +.060" / STDother_service
4333991Cylinder Liner QSK19 STD/STDother_service
4371771Cylinder Liner Kit +.020" / +.020"other_service
4371772Cylinder Liner Kit +.060" / +.020"other_service
4371773Cylinder Liner Kit +.060" / STDother_service
4371779Cylinder Liner Kit QSK19 STD/STDother_service
47 150 03-SBreaker Pointsother_service
4910463Piston QSK19R/Mother_service
4910465Piston QSK Seriesother_service
4916177Piston GTA/GQSK19other_service
4918058Piston QSK19CEother_service
4922319Piston QSK19Cother_service
4955233Piston Kit QSK19R/Mother_service
4955235Piston Kit QSK Seriesother_service
4955236Piston Kit QSK19Cother_service
4955238Piston Kit GTA/GQSK19other_service
52 098 12-SBendix Drive 9-Toothother_service
52 755 13-SCondenserother_service
52 755 48-SIgnition Coil (Battery)other_service
KTA19Engine Modelother_service
M-205080Regulator Plungerother_service
M-205091Valve Locksother_service
M-205093Exhaust Valve Seatother_service
M-205094Valve Spring Retainerother_service
M-205840Connecting Rod Bearing STDother_service
M-205841Connecting Rod Bearing .010other_service
M-205842Connecting Rod Bearing .020other_service
M-205843Connecting Rod Bearing .030other_service
M-3002834Camshaft Bearingother_service
M-3007525Cylinder Liner Kitother_service
M-3022157Cylinder Linerother_service
M-3035362Shut-off Valve Assy 24Vother_service
M-3043909Connecting Rod Bushingother_service
M-3052819Intake Valve Seat - Tribaloyother_service
M-3066877Camshaftother_service
M-3066882Camshaft variantother_service
M-3202210Valve Guideother_service
M-3643725Valve Springother_service
M-4009220Cylinder Liner KT19 Thick Flangeother_service
M-4009227Cylinder Liner KT19other_service
M-4024767Liner Kit KT19 Thick Flangeother_service
M-4024770Liner Kit KT19other_service
M-4024808Solenoid Repair Kit 12Vother_service
M-4024809Solenoid Repair Kit 24Vother_service
M-AR12270Main Bearing Set STDother_service
M-AR12271Main Bearing Set .010other_service
M-AR12272Main Bearing Set .020other_service
M-AR12273Main Bearing Set .030other_service
52 559 03-SMechanical Fuel Pumppump
M-3011389Water Pumppump
M-3047549Lube Oil Pump Assypump
M-3803153Water Pump Repair Kitpump
M-69521Pump Bushingspump
4308809Flat Seal for Cylinder Linerseal
4333984D-Type Seal Linerseal
4371769Seal Kitseal
4371770D-Type Seal Kitseal
M-186780Sealseal
M-205898Pump Mounting O-ringseal
M-207135Pump Mounting Sealseal
M-3007517Piston Cooling Nozzle with sealseal
M-3035342Banjo Sealing Washerseal
52 132 02-SSpark Plugspark_plug
M-3076489Thermostat 180Fthermostat
M-3032634Turbocharger Repair Kit T18Aturbocharger
M-3803257Turbocharger Repair Kit HC5Aturbocharger

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 KT19?

The Cummins/Onan KT19 has a displacement of 18.7 liters.

Which generators use the Cummins/Onan KT19 engine?

The Cummins/Onan KT19 powers 3 generator set(s), including AKSA AC500, AKSA AC550, Cummins/Onan Kt19.

How often should you change the oil in the Cummins/Onan KT19?

The Cummins/Onan KT19 oil change interval is every 1500 hours.

What is a common problem with the Cummins/Onan KT19 engine?

A commonly reported issue on generators using the Cummins/Onan KT19 is: White Smoke or Rough Running At Idle (After Warmup Period). Cause: Low Coolant Temperature. Fix: Refer to “Coolant Temperature Below Normal” chart..