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Kohler KD 626/3 Engine

The Kohler KD 626/3 is a 1.87 L 3-cylinder na engine rated at 3000 rpm, producing up to 28 kW. It powers generator sets from Kohler, including the KD 626-3. It holds 5 L (1.3 gal) of oil and 24 L (6.3 gal) of coolant.

Also known as: KOHLER KD 626/3

1.87 L
Displacement
3
Cylinders
3000 rpm
Rated speed
28 kW
Gross power

Engine specifications

Oil capacity5.0 L
Coolant capacity24.0 L
Displacement1.87 L
Cylinders3
AspirationNA
Rated speed3000 rpm
Gross power28 kW

Maintenance schedule

ItemSpecCapacityPart #Interval
Air filter—
Fuel filter—3 hr
Oil filter1460-00950 hr Amazon eBay $90.15 FridayParts $156.41
BatteryDry air cleaner external cartridge, Dry air cleaner internal cartridge—3 hr
BeltBlower belt—50 hr
Coolant filter—
OilSAE 10W-30, SAE 15W-40, SAE 20W-60, SAE 5W-40, SAE 0W-30, SAE 20W*15.0 L—50 hr
Spark plugValve/rocker arms clearance adjustment, Setting and injectors cleaning—50 hr

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

Service intervals

2
ItemActionHoursMonthsNotes
Engine lubricantChange50 hrFirst service — After the first 50 working hours; schedule columns are 10 / 125 / 250 / 500 / 1000 / 2500 / 5000 hours (*) in case of low use: every year; (**) in case of low use: every 2 years; (***) depends on the environment
Oil filterReplace50 hrFirst service — After the first 50 working hours

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

60
TypeItemValueUnitCondition
ClearanceCamshaft end play0,15 ÷ 0,30mmcylinder head, injection pump and fuel feed pump removed
ClearanceCompression release clearance A0,30 ÷ 0,40mmpiston at top dead centre on compression stroke
ClearanceConnecting rod axial misalignment0,02mmmaximum limit 0,05 mm
ClearanceCrankshaft end play0,20 ÷ 0,30mmafter refitting crankshaft pulley and tightening nut at 300 Nm; not adjustable
ClearanceCylinder bore wear limit0,10mmif exceeded, bore cylinder and fit oversize piston and rings
ClearanceInjector protrusion (nozzle end to head surface A)3 ÷ 3,5mmcylinder head disassembled
ClearanceOil pump control shaft end float0,040 ÷ 0,090mmlimit value 0,170 mm
ClearanceOil pump gear edge to pump body clearance0,041 ÷ 0,053mmlimit value 0,10 mm
ClearancePiston clearance volume, size P injectors0,55 ÷ 0,6mm
ClearancePiston clearance volume, size S injectors0,65 ÷ 0,7mm
ClearanceRocker arm to axle clearance (replace axle and rocker arm if greater)0,135mmlimit value
GapAir gap, 12 V 21 A alternator armature winding to inductor0,47 ÷ 0,63mm
GapAir gap, 12,5 V 14 A alternator armature winding to inductor0,55 ÷ 0,63mm
GapMetal snap ring end gap A (compression, chrome-plated)0,07 ÷ 0,11mmlimit value 0,20 mm
GapMetal snap ring end gap B (conical internal torsional)0,05 ÷ 0,09mmlimit value 0,16 mm
GapMetal snap ring end gap C (oil scraper)0,04 ÷ 0,08mmlimit value 0,15 mm
GapPhase sensor air gap0,3 ÷ 0,5mmadjusted with 0,2 mm shims
OtherBlower belt tension check5 ÷ 15mm4 Kg load located halfway between the pulleys
OtherConnecting rod weight difference limit when replacing10g
OtherCylinder average roughness0,5 ÷ 1µm
OtherCylinder cross hatch pattern115° ÷ 140°degreesuniform and clear in both directions
OtherFuel feeding pump minimum delivery at 1500 r.p.m.64l/hself-regulation pressure 4 ÷ 5 m water column
OtherIntake/exhaust cam height H33,65 ÷ 33,55mmengines EPA 97/68 CE; replace camshaft if H is 0.1 mm below given value
OtherOil pump delivery at 3000 r.p.m.18liters/min
OtherPhase sensor pin length (magnetic end to sensor support surface)30,24 ÷ 30,26mm
OtherPhase sensor tolerance30,015 ÷ 30,035mmchecked with gauge
OtherPiston diameter measured at 2 mm from the base94.90 ÷ 94.92mmreplace piston and snap rings if wear greater than 0,05 mm of minimum value
OtherPiston weight difference limit when replacing6g
OtherValve spring free length A52mm
OtherValve spring length compressed by a 21 Kg weight34.8mm
OtherValve spring length compressed by a 32 Kg weight25.8mm
OtherValve timing - exhaust valve closing (delta)2° after P.M.S.valve clearance = 0.65 ÷ 0.70 mm
OtherValve timing - exhaust valve opening (gamma)34° before P.M.I.valve clearance = 0.65 ÷ 0.70 mm
OtherValve timing - intake valve closing (beta)34° after P.M.I.valve clearance = 0.65 ÷ 0.70 mm
OtherValve timing - intake valve opening (alpha)2° before P.M.S.valve clearance = 0.65 ÷ 0.70 mm
PressureFuel filter max. working pressure4bar
PressureInjection pump delivery valve sealing - pressure drop30 ÷ 50barrack at half-stroke
PressureInjector setting pressure, size P245 ÷ 255bar
PressureInjector setting pressure, size S210 ÷ 220bar
PressureOil filter cartridge by-pass valve opening pressure1,4 ÷ 1,8bar
PressureOil filter cartridge max. working pressure13bar
PressurePlunger internal leakage - replace plunger if displayed pressure below300barrack rod at half-stroke
SpeedFull speed stabilization at pre-set power3000r.p.m.
SpeedFull speed, no load3200r.p.m.
SpeedIdling speed, no load800 ÷ 900r.p.m.after warming up 10 minutes
TemperatureCylinder head heating for valve guide insertion160 ÷ 180°C
TemperatureLube oil peak temperature, engines with oil coolerbelow 110°C
TemperatureLube oil peak temperature, engines without oil coolerbelow 120°C
TemperatureStarter ring gear heating300°Cfor 15 ÷ 20 minutes
TorqueAir filter fastening nuts to intake manifold25Nm
TorqueBelt guard screws15Nm
TorqueBlower belt half-pulley fastening nuts10Nmnut in position A when tightened
TorqueBlower control pulley bolt300Nmleft-handed bolt
TorqueBlower control pulley left-handed fastening bolts (variator)300Nm
TorqueCamshaft gear nut25Nm
TorqueCamshaft timing bolt250Nm
TorqueConnecting rod big end bolts40Nm
TorqueCrankshaft center main bearing support screws30Nm
TorqueCylinder head fastening nuts55Nmtightened gradually in sequence 1, 2, 3, 4
TorqueExhaust manifold nuts20Nmtighten in sequence and gradually before final torque

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
Engine oilSAE 0W30below -15°CFor a temperature of -15°C an oil with a 0W30 viscosity is recommended; in countries where AGIP products are not available use oil API SJ/CF for Diesel engines or MIL-L-2104 D/E
Engine oilSAE 15W40API CF 4 / ACEA B2 - E2 / MIL-L-2104 D/E5.5 lOil volume at max level (oil filter included); oil changes to the upper level of the rod
Engine oilSAE 5W40-15°C to -10°CFor a temperature of -10°C an oil with a 5W40 viscosity is recommended
FuelDieselCetane number minimum 5115.0 lCapacities standard fuel tank 15 litres; viscosity 2.0/4.5 centistokes at 40°C; density 0.835/0.855 Kg/litre; distillation 85% at 350°; sulphur maximum 0.05% of the weight; winter fuels: summer up to 0°C, winter up to -10°C, alpine up to -20°C, arctic up to -30°C; aviation fuels JP5, JP4, JP8 and JET-A if 5% oil is added
GreaseMolikote BR2 PlusLubricate the inside of the valve stem sealing rings and the valve stem

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

Procedures

12
(Static) Injection timing check and adjustment adjustment

Tools: 1460-266, 1460-275, 1460-274, 1460-270, 1460-024, 1460-273

  1. Remove the rocker arm cover.
  2. Assemble tool 1460-266 (lever 1460-275, dial indicator 1460-274 in holder 1460-270).
  3. Insert capillary tester 1460-024 onto the injection pump union.
  4. Connect high-pressure pump 1460-273 supplied by a tank at least 100 mm above the injection pump.
  5. Unscrew the fuel supply union for the injection pump of the cylinder to be worked on.
  6. Rotate the crankshaft anticlockwise until diesel starts to flow out from the capillary.
  7. Change direction of rotation clockwise from the timing belt side.
  8. Press the high-pressure lever and rotate until fuel stops flowing from the capillary.
  9. Press the lever to bring the valve into contact with the piston crown; find dead centre and reset dial indicator to zero.
  10. Rotate the crankshaft clockwise and position the cylinder piston at top dead centre.
  11. Read piston lowering in mm and convert to degrees with the conversion table.
  12. Adjust static advance by adding seals G (to delay) or removing seals G (to advance); repeat for each cylinder.
Blower belt tension adjustment adjustment

⚠ Check the belt tension only when the engine is stopped

Tools: Spacers 0.5, 1 and 2 mm

  1. Check the belt tension only when the engine is not running.
  2. Add spacers (to reduce tension) or remove spacers (to increase tension) between the half-pulleys.
  3. Spacers are available in thicknesses of 0.5, 1 and 2 mm.
  4. Check with a 4 Kg load halfway between the pulleys: bend should be 5 ÷ 15 mm.
Idling and full speed setting (no load, standard) adjustment
  1. Fill with oil and fuel, start the engine and let it warm up for 10 minutes.
  2. Adjust idling speed at 800 ÷ 900 r.p.m. by turning setscrew 1; tighten lock nut.
  3. Turn screw 2 and set full speed in no-load conditions at 3200 r.p.m.; tighten lock nut.
Injection pump delivery setting adjustment
  1. Perform setting at the torque dynamometer; otherwise it is only approximate.
  2. Loosen delivery limiting device C by 5 turns.
  3. Bring engine to full speed in no-load conditions, i.e. 3200 r.p.m.
  4. Tighten limiting device until the engine shows a drop in r.p.m.
  5. Unscrew limiting device C by 1½ turn.
  6. Tighten lock nut.
Phase sensor air gap adjustment adjustment

Tools: 0,2 mm shims, Torque wrench

  1. The air gap is adjusted using shims measuring 0,2 mm placed between the sensor surface and its support.
  2. The air gap must be between 0,3 and 0,5 mm.
  3. Consider any difference between measured sensor pin length and depth between sensor support surface and camshaft and specifications.
Stop setting adjustment
  1. Remove fuel feeding pump and cover.
  2. Loosen both bolts fixing plate A.
  3. Push injection pump B control rod to the right and keep it in this position.
  4. Push plate A to the right until it touches rod B and stop.
  5. Release rod B and push plate A to the right so that rod B has a stroke of 1 mm.
  6. Tighten both bolts.
Valve / rocker arm clearance adjustment adjustment

⚠ Make settings when the engine is cold

Tools: Thickness gauge, Cross-head screwdriver, Torque wrench

  1. Make settings when the engine is cold.
  2. Remove the rocker arm covers and check that seals are intact, otherwise replace.
  3. Bring the cylinder piston to be adjusted to the compression top dead centre.
  4. Loosen the fastening nut C, insert the thickness gauge D between rocker arm and valve stem.
  5. Turn adjusting screw B with a cross-head screwdriver to set clearance.
  6. Tighten fastening screw C and recheck clearance.
  7. Refit cover, tighten screws to 20 Nm.
Oil pressure check diagnostic

Tools: 10 bar pressure gauge

  1. Once the engine is fitted, fill with oil and fuel.
  2. Connect a 10 bar pressure gauge to the oil filter fitting.
  3. Start the engine and check pressure as a function of the oil temperature.
Phase sensor check with dial indicator diagnostic

Tools: Dial indicator, Support for dial indicator, Gauge, Master

  1. Assemble dial indicator 1 onto support 2.
  2. Attach the support with dial indicator to gauge 3.
  3. Insert master 4 into gauge 3 and reset the dial indicator.
  4. Remove the master from the gauge; insert the phase sensor.
  5. Check that the sensor falls within tolerance measurements of 30,015 ÷ 30,035 mm.
Voltage regulator operation check diagnostic

⚠ When the engine is running do not disconnect battery cables or remove the key from the control panel

⚠ Keep regulator away from heat sources (above 75°C may damage it)

⚠ No electric welding on engine or application

Tools: d.c. voltmeter, Ammeter (14 or 21 A, withstand 400 ÷ 450 A)

  1. Check that connections correspond to the layout.
  2. Disconnect the terminal from the battery positive pole.
  3. Connect a d.c. voltmeter between the two battery poles.
  4. Fit an ammeter between the positive pole and the corresponding cable 1 terminal.
  5. Start a couple of times until battery voltage drops below 13 V.
  6. When battery voltage reaches 14,5 V the ammeter current suddenly drops to almost zero.
  7. Replace regulator if recharge current is zero with voltage below 14 V.
Oil-bath air cleaner cleaning maintenance

⚠ Do not blow the paper filter element with compressed air to clean

⚠ Check gaskets and replace as necessary

⚠ The cyclone pre-filter cup must not be filled with oil

Tools: Compressed air

  1. Thoroughly clean the lower tank and the metal filter element using diesel fuel, then blow compressed air into them.
  2. Clean the upper polyurethane foam filter element by washing it in soapy water.
  3. Dry completely using compressed air.
  4. After cleaning refill the engine oil tank up to the indicated level.
Procedures to be carried out before starting the engine after storage maintenance
  1. Remove all protections and coverings.
  2. Remove the rust preventer from the external part of the engine with solvent or degreaser.
  3. Tension the blower timing belt.
  4. Disassemble the injectors and introduce motor oil on the piston crown (no more than 2 cc for every cylinder).
  5. Remove valve covers, spray motor oil on the valves and turn the crankshaft manually for a few revolutions.
  6. Start the engine and heat it for about 10 minutes.
  7. Remove the drain plug and let the protective oil flow completely.
  8. Reinsert the drain plug.
  9. Refill motor oil to the upper level of the rod using the recommended oil.

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 Kohler KD 626/3?

The Kohler KD 626/3 engine has an oil capacity of 5.0 liters.

What is the displacement of the Kohler KD 626/3?

The Kohler KD 626/3 has a displacement of 1.87 liters with 3 cylinders.

Which generators use the Kohler KD 626/3 engine?

The Kohler KD 626/3 powers 1 generator set(s), including Kohler KD 626-3.

How often should you change the oil in the Kohler KD 626/3?

The Kohler KD 626/3 oil change interval is every 50 hours.