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Waukesha L1616-GSIU Engine

The Waukesha L1616-GSIU is a 26.4 L 12-cylinder turbocharged engine rated at 1800 rpm, producing up to 700 kW. It powers generator sets from Cummins/Onan, including the WF series and WK Series. It holds 25 L (6.6 gal) of oil and 25 L (6.6 gal) of coolant.

Also known as: Waukesha L1616-GSIU

Part of the Waukesha L1616 engine family — 4 variants share parts & fitment.

26.4 L

Displacement

Cylinders

1800 rpm

Rated speed

700 kW

Gross power

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

Engine specifications

Oil capacity	25.0 L
Coolant capacity	25.0 L
Displacement	26.4 L
Cylinders	12
Aspiration	Turbocharged
Rated speed	1800 rpm
Gross power	700 kW

Generator sets powered by this engine

Cummins/Onan WF seriesCummins/Onan WK Series

Common problems

Overspeed lamp lights - no fault condition exists.
Fix: Replace overspeed circuit board.
Overcrank fault lamp lights and engine stops cranking after approximately 75 seconds.
Fix: See engine service manual for troubleshooting fuel system, ignition system, etc. After correcting problem, reset the engine monitor by moving run-stop-remote switch to stop position, and depressing reset switch. PENN STATE. Move and hold run-stop-remote switch to OFF. Press reset, release and move switch to ON.
Overcrank fault lamp lights after engine has run for approximately 75 seconds.
Fix: Replace start-disconnect circuit board.
Low oil pressure lamp lights after engine is running.
Fix: Check: a. Oil level - engine will shut down after approximately 12-1/2 seconds if oil pressure is low.
Low oil pressure fault lamp lights - no fault condition exists.
Fix: Be certain that no fault condition exists. Disconnect lead 30 from T B l l inside control box (refer to wiring diagram). If low oil pressure lamp still lights, remove and replace engine monitor plug-in printed circuit board.
High engine temperature lamp lights as soon as engine starts.
Fix: Check for defective sensor or actual high temperature condition.
High engine temperature lamp lights after engine is running.
Fix: Check for: a. Defective thermostat/thermostats. b. Low coolant level. c. Defective high engine temperature sensor.
Fault lamp lights immediately after engine starts.
Fix: Check for: a. overspeed condition as engine starts. b. high temperature condition. c. faulty high engine temperature sensor or overspeed switch. d. faulty starter disconnect.
Fault lamp lights and engine stops cranking after approximately 75 seconds.
Fix: See engine service manual for troubleshooting fuel system, ignition system, etc. After correcting problem, reset the engine monitor by holding run-stop-remote switch in stop position, and depressing reset switch. Release and return to run position.
Fault lamp lights afterengine is running.
Fix: Check the following: a. Oil level-engine will shut down after approximately 12-1/2 seconds if low oil pressure sensor does not open. b. Oil pressure sensor may be defective. c. High engine temperature - caused by low coolant level, faulty thermostat, etc. d. Faulty high engine temperature sensor. e. Faulty starter disconnect.
Fault lamp lights - no fault condition exists.
Fix: Be certain that no fault condition exists. Disconnect lead 30 and 31 from T B l l inside control box (refer to wiring diagram). If fault lamp still lights with leads disconnected, remove and replace engine monitor plug-in printed circuit board.

Compiled from service & troubleshooting documentation across every generator set that uses the Waukesha L1616-GSIU.

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter	Air Filter		—	200 hr
Fuel filter	Fuel Filter		—	200 hr
Oil filter	Oil Filter		232AI489	200 hr	Amazon eBay
Battery	Battery		—	200 hr
Belt	Drive Belt		—	200 hr
Coolant	Coolant	25.0 gallons	—	200 hr
Oil	Engine Oil	25.0 gallons	232AI490	200 hr	Amazon eBay PartsGeek $17.97
Spark plug	Spark Plug		—	200 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	Notes
Crankcase oil	Change	100 hr	Under dust and dirt conditions: change crankcase oil at least every 100 operating hours
Coolant	Check		First service — On initial run, check coolant level several times and add liquid to compensate for air pockets
Generating plant	Other		First service — Break-in: run plant at 50% rated load for the first 1/2 hour after reaching operating temperature

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
Clearance	Generator support to skid base shim clearance	.035	inches	added to each side of the skid base
Other	BHP at 1,800 rpm (nominal)	700		1,800 rpm
Other	Battery charging rate, initial	2 to 10	amperes	when plant first starts
Other	Battery electrolyte specific gravity, diluted (hot locations)	1.225		ambient above 90°F
Other	Battery electrolyte specific gravity, full charge	1.275
Other	Cranking limiter time limit	45	seconds
Other	Maximum crank time	30	seconds	do not crank longer at one time
Pressure	Low oil pressure cut-out (shutdown)	14	psi	shuts down if oil pressure drops below
Pressure	Normal engine oil pressure	40-50	psi	at operating temperature
Speed	50 cycle operating speed	1500	rpm
Speed	60 cycle operating speed	1800	rpm
Speed	AC frequency regulation	5	%
Speed	Governor regulation	5	%
Speed	Overspeed shutdown	2100	rpm	shuts down if plant speed exceeds
Temperature	City water cooling flow adjustment (water temperature)	165-195	°F	maintain while viewing water temperature gauge
Temperature	High water temperature cut-out	215	°F	shutdown above
Temperature	Normal operating water/coolant temperature	160-180	°F
Torque	Alternator torque REF 1	30	in.-lb.
Torque	Alternator torque REF 2	30-35	ft.-lb.
Torque	Alternator torque REF 3	450-500	ft.-lb.
Torque	Alternator torque REF 4	150-200	ft.-lb.
Torque	Alternator torque REF 5	195-200	ft.-lb.
Torque	Alternator torque REF 6	275-280	ft.-lb.
Torque	Alternator torque REF 7	120-125	ft.-lb.
Torque	Alternator torque REF 8	25	ft.-lb.	min.
Torque	Alternator torque REF 9	7-10	ft.-lb.
Torque	Diodes (rotating rectifier)	30	in. lb.	or finger tight plus a quarter turn
Voltage	AC voltage regulation	±2	%

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	Capacity	Notes
Coolant	Clean soft water		51.0 gallons	Cooling system capacity including radiator. Use a good rust and scale inhibitor; use ethylene glycol base antifreeze if exposed to freezing temperatures. Maintain 165°F to 195°F.
Engine oil		MIL-L-2104B military specification (oils designated for MS or DG service)	25.0 U.S. gallons	Approximate oil pan capacity; extra oil may be required for oil filter or accessories. Do not use multi-viscosity oil such as 10W-30; do not mix brands or grades. Use oil of recommended viscosity according to ambient temperature.
Fuel	Natural gas			Refer to Waukesha manual for fuel specifications; keep fuel supply clean

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

Procedures

Testing Rotating Rectifier Assembly (Diodes) diagnostic

Tools: ohmmeter

Remove access cover from exciter end of the generator.
Isolate each diode by disconnecting one end from its connection point.
Use an ohmmeter to measure resistance in the individual diode; reverse the ohmmeter leads and repeat.
A good diode should have a high resistance value one way and a low value when leads are reversed; replace if not good.
Check all diodes in accordance with step 3.

Align Generator Support to Skid Base installation

⚠ The generator support must be aligned to the skid base to prevent premature generator bearing failure; failure to do so could void the warranty.

Tools: feeler gauge or dial indicator, jackscrews

Set plant on its mounting foundation using vibration isolators; secure skid base to foundation.
Remove the two mounting bolts and shims securing the generator support to the skid base.
Use the mounting bolts as jackscrews in the threaded holes; remove tension and allow generator to hang free.
Measure clearance from top of skid base to each generator support mounting surface.
Add .035 inches to each side of the skid base; this determines the amount of shims required.
Turn jackscrews to allow clearance for placing shims between skid base and generator support.
Lower generator on shims and recheck total clearance (must equal base-to-support clearance plus .035 in.).
Remove jackscrews and install as mounting bolts through generator support, shims and skid base; secure and lock.

Battery Electrolyte Dilution for Hot Locations maintenance

⚠ Avoid skin or clothing contact with electrolyte; dispose of it in a safe manner.

Tools: hydrometer or filler bulb

Fully charge the battery.
With battery still on charge, draw off all electrolyte above the plates in each cell; do not pour off.
Refill each cell with distilled water to normal level.
Continue charging for one hour at a 4- to 6 ampere rate.
Test each cell; if specific gravity is still above 1.225, repeat steps 2, 3 and 4.

Out-Of-Service Protection (More Than 30 Days) maintenance

Run plant until thoroughly warm.
Drain oil from oil base while still warm; refill and attach a warning tag stating oil viscosity used.
Remove each spark plug; pour one ounce of rust inhibitor (or SAE #50 oil) into each cylinder; install spark plug.
Service air cleaners as outlined in Waukesha manual.
Clean throttle linkage and protect by wrapping with a clean cloth.
Plug exhaust outlets to prevent entrance of moisture, bugs, dirt, etc.
Wipe entire unit; coat parts susceptible to rust with a light film of grease or oil.
If battery is used, disconnect and follow standard battery storage procedure.
Provide a suitable cover for the entire unit.

Starting the Plant operation

Press the RUN-STOP switch to its RUN position, holding in contact to crank the engine.
Do not crank for more than 30 seconds at one time; investigate any failure to start.
If engine fails to crank, check that the cranking limiter switch is closed.

Stopping the Plant operation

If conditions permit, disconnect electrical load and allow the plant to run a few minutes at no load.
Press the RUN-STOP switch to its STOP position to stop the plant.

Brush Assembly Removal (Battery Charging DC Alternator) repair

Remove the three No. 10-24 screws which fasten voltage regulator to DC alternator; remove regulator to gain access to phenolic cover, disconnecting leads as required.
Remove the two No. 8-32 screws on phenolic cover and lift out cover and gasket.
Pull brush assembly straight up and lift out.
For reassembly, reverse procedure.

Replacement of Diodes repair

⚠ Do not over-torque the diode.

Tools: proper size wrenches

Use proper size wrenches to hold the body of the diode while removing the nut attaching it to the heat sink.
Push the diode free of its mounting hole in the heat sink.
Be sure new diode is installed in the same position (direction) as defective diode; parts have directional arrows.
Insert new diode into its mounting hole in the heat sink.
Using nut and washer provided, secure diode, being careful not to allow it to turn while tightening; do not over-torque.
Connect leadwires to appropriate terminals.
Replace access cover.

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

Voltage	Phase	Connection	Leads	Notes
120/240	3	4 Wire Delta	L0 (neutral), L1, L2, L3	Supplies 120 volt single phase and 240 volt three phase. For 3 phase operation L0 is not used; L1 and L2 are 'hot' terminals and L0 is the neutral (can be grounded if required). If no 3 phase output used, usable 1 phase output is 2/3 of 3 phase KVA.
Three phase	3	3 Phase, 3 Wire	L1, L2, L3	No terminal is grounded. Connect separate load wires to each plant terminal L1, L2 and L3. Single phase obtained from any two terminals (L1-L2, L1-L3, L2-L3); load on any one single-phase circuit must not be greater than 1/3 rated capacity.
Three phase, 4 wire (Wye)	3	Wye connected	L0 (grounded neutral), L1, L2, L3	Single phase voltage is the lower nameplate voltage; three phase voltage is the higher nameplate voltage. Connect neutral (white) to L0 and hot (black) to L1, L2 or L3; not more than 1/3 rated capacity from any one circuit.

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 Waukesha L1616 family

109

Part #	Description	Category
302A61	Ammeter, Charge	Ammeter
302P640	Ammeter, AC (Check Ammeter Scale - Select According to Rating)	Ammeter
302P641	Ammeter, AC (Check Ammeter Scale - Select According to Rating)	Ammeter
302P642	Ammeter, AC (Check Ammeter Scale - Select According to Rating)	Ammeter
A956	2-12 VOLT BATTERIES	Battery
332A795	Ammeter, Charge (30-0-30)	Block
332AI006	Block, Terminal	Block
332AI009	Block, Terminal	Block
301D2903	Box, Control	Box
130-0465	Brace	Brace
130-0466	Brace	Brace
301A2393	Bracket, Relay Mounting	Bracket
322P69	Bracket, Mounting - Engine	Bracket
110-1168	Bracket & Nipple Assembly	Bracket nipple
505-0270	Bushing, Reducer (2 x 1-1/4")	Bushing reducer
503-0059	Clamp	Clamp
330A5	Cover - BOI	Cover
505-0453	Elbow (90° )	Elbow 90
130-0740	Flange Assembly	Flange assembly
232AI490	Engine Oil	Fluid
301C2906	Frame. Control Panel Mounting	Frame
232AI817	Onan OE Filter	Fuel filter
A955	Fill pipe for underground fuel tank	Fuel tank
193B112	Gauge, Water Temperature	Gauge
193B194	Gauge, Oil Pressure	Gauge
502-0391	Adapter, Hose	Hose
503-0359	Hose (1-5/8" I.D. x 3 ' )'	Hose
503-0512	Hose (2-7/8" I.D. x 18" )	Hose
322P74	Knob, Rheostat	Knob
322-17	Bulb, (2) Panel ( I ) Pilot	Lamp
322-81	Lamp, Panel	Lamp
309-0243	Valve, Control - Temperature Regulating	Marsh valve
302B213	Meter, Frequency (60 Hertz)	Meter
302B234	Meter, Frequency (50 Hertz)	Meter
302P465	RESISTOR-STABILIZING	Meter
302P466	For 220/380-V, 3-Ph, 60-Cycle (Model H)	Meter
302P468	For 120/208-V,120/240-V, & 347/600-V 3PH. 50 Cy!. (825-Ohm, 75-Watt)	Meter
302P469	For 220/380-V, 3Ph. 50-Cycle	Meter
302P470	For 277/480-V, 3-Ph, 50-Cyclo (5-P!)	Meter
402A70	Mount, Rubber - Control Box.Frame	Mount
505-0328	Nipple ( 3 x 6 " )	Nipple
505-0604	Nipple (3 x 9-3/4" )	Nipple
505-0615	Nipple (3 x 24" )	Nipple
505-0437	Nipple, Half (1-1/4 x 4")	Nipple half
130-0687	Standpipe	Service part / kit
232A90	Shim (0.020 inch thick, 2 x 3 gauge metal)	Service part / kit
232AI489	Laminated Shim	Service part / kit
301A1914	Bracket, Panel Stop	Service part / kit
302A6I	Switch, Panel Light	Service part / kit
302P422	Scale Reads 0-600	Service part / kit
302P467	For 277/480 Volt,3 Phase, 60 Cycle Plants.	Service part / kit
304A262	RESISTOR. FIXED 50-Ohm, 10 Watt	Service part / kit
304A446	RESISTOR. FIXED 150-Ohm, 10 Wan	Service part / kit
307-0839	Valve, Solenoid	Service part / kit
307-0844	Valve, Solenoid	Service part / kit
307A655	Relay, Emergency Latch	Service part / kit
307A899	Relay, Oil Pressure	Service part / kit
307P778	Spring, Relay Hold-down	Service part / kit
308-2	Switch, Panel Light	Service part / kit
308PI38	Strip, Blk. Marker (55 through 62)	Service part / kit
30IAI685	Block, Terminal (8-Place)	Service part / kit
30ID2I24	Cover, Output Terminal Box	Service part / kit
320AI04	Limiter, Cranking	Service part / kit
323-52	Socket	Service part / kit
332AI005	Block, Terminal (20-Place)	Service part / kit
501-0186	Line, Flexible	Service part / kit
501-0187	Line, Flexible	Service part / kit
504-0003	Cock, Drain (1/4 NPT)	Service part / kit
504-0062	Valve, Relief	Service part / kit
505-0004	Nipple, Pipe (1.0 x 1.50)	Service part / kit
505-0041	Elbow, Pipe ( 1 " x 90°)	Service part / kit
505-0088	Nipple, Pipe (1 x 4-1/2")	Service part / kit
505-0178-	Nipple; Half	Service part / kit
505-0258	Nipple (1-1/4 x 3")	Service part / kit
505-0394	Bushing, Reducer (2 x 1")	Service part / kit
505-0669	Tee	Service part / kit
505-0679	Nipple (3 x 12" )	Service part / kit
800-0091	Part 800-0091	Service part / kit
850-0040	Washer, Lock - Spring (1/4")	Service part / kit
850-0060	Screw, Cap - Hex Head (5/16-18 X 7-1/2" )	Service part / kit
862-0001	Nut, Hex (1/4-20)	Service part / kit
862-0005	Nut (1/2-13)	Service part / kit
I93BI94	Gauge, Oil Pressure	Service part / kit
TB12	terminal block for remote connections and common alarm (inside control)	Service part / kit
TB21	TERMINAL BLOCK	Service part / kit
301C2908	Panel. Control	Panel
301C2915	Panel, Control	Panel
304A305	Panel Only, Lower Cont.	Panel
301A2905	Plate. Control Box - Side	Plate
301B2904	Plate. Control Box - Top	Plate
308-3	Plate, On-Off Switch	Plate
322-73	Receptacle, Panel Lamp	Receptacle
322P73	Receptacle, Panel Lamp	Receptacle
307P820	Relay, Adjustabe Start Disconnect & Crankshaft Limiter	Relay
320B259	Relay, Cranking	Relay
304A66	Resistor, 4xELI	Resistor
322-65	Resistor. Adjustable - 45,000 Ohm, lOWatt (277/480 V o l t )	Resistor
308-13	Rheostat, Voltage Adjustment	Rheostat
337-44	Strap, Ground	Strap
332AI134	Strip,. Terminal Block Marker	Strip
308P138	Switch, Run-Stop-Remote	Switch
308P139	Switch, Voltage & Current Selector	Switch
309P253	THEHCOSTAT	Thehcostat
333PI3B	TheHCostat	Thehcostat
302B645	Transformer, Current (Check Transformer Nameplate - Select According to Rating)	Transformer
302P643	Transformer, Current (Check Transformer Nameplate - Select According to Rating)	Transformer
302P644	Transformer, Current (Check Transformer Nameplate - Select According to Rating)	Transformer
315B292	Transformer, Potential (120/208 V o l t Plants)	Transformer
302P421	Scale Reads 0-300	Voltmeter

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 oil capacity of the Waukesha L1616-GSIU?

The Waukesha L1616-GSIU engine has an oil capacity of 25.0 liters.

What is the displacement of the Waukesha L1616-GSIU?

The Waukesha L1616-GSIU has a displacement of 26.4 liters with 12 cylinders.

Which generators use the Waukesha L1616-GSIU engine?

The Waukesha L1616-GSIU powers 2 generator set(s), including Cummins/Onan WF series, Cummins/Onan WK Series.

How often should you change the oil in the Waukesha L1616-GSIU?

The Waukesha L1616-GSIU oil change interval is every 200 hours.

What is a common problem with the Waukesha L1616-GSIU engine?

A commonly reported issue on generators using the Waukesha L1616-GSIU is: Overspeed lamp lights - no fault condition exists.. Fix: Replace overspeed circuit board..