Kohler KDI 2504TCR Engine
The Kohler KDI 2504TCR is a 2.48 L 4-cylinder turbo+ charge after cooler engine rated at 1800 rpm, producing up to 66.7 kW. It powers generator sets from Kohler, including the 45 REOZT4 and KDI 2504 TCR. It holds 11.5 L (3.0 gal) of oil and 17.2 L (4.5 gal) of coolant.
Also known as: Kohler KDI 2504TCR
Part of the Kohler KDI2504 engine family — 15 variants share parts & fitment.
Engine specifications
| Oil capacity | 11.5 L |
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| Coolant capacity | 17.2 L |
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| Displacement | 2.482 L |
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| Cylinders | 4 |
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| Aspiration | Turbo+ Charge After Cooler |
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| Rated speed | 1800 rpm |
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| Gross power | 66 kW |
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Common problems
15- Warning YELLOW light turn on
Cause: Engine ECU has detect a malfunctions
Fix: Contact REHLKO authorised workshops - Warning RED light turn on
Cause: Engine ECU has detect a malfunctions
Fix: Contact KOHLER authorised workshops - The engine starts but stops
Cause: Inefficient electrical connections
Fix: Clean the electrical contacts - The engine does not start
Cause: Sulphated battery terminals corroded
Fix: Clean the battery terminals - The engine does not rev up
Cause: Inefficient electrical connections
Fix: Clean the electrical contacts; if the problem persists, Contact REHLKO authorised workshops - Slow acceleration
Cause: Clogged fuel filter
Fix: Replace the fuel filter - RPM instability at idle speed
Cause: Clogged fuel pipes
Fix: Contact REHLKO authorised workshops - Poor quality fuel
Fix: Clean the tank and refuel with quality fuel - Numero dei giri al minimo basso
Cause: Clogged fuel pipes
Fix: Contact KOHLER authorised workshops - Low idle speed
Cause: Clogged fuel pipes
Fix: Contact REHLKO authorised workshops - Excessive fuel consumption
Cause: Clogged air filter
Fix: Replace with a new filter - Engine starts but stops
Cause: Inefficient electrical connections
Fix: Clean the electrical contacts - Engine overheats
Cause: Insufficient coolant level
Fix: Fill up to the level - Engine lost its initial performance
Cause: Clogged air filter
Fix: Replace with a new filter - Engine jerking
Cause: Clogged fuel pipes
Fix: Contact REHLKO authorised workshops
Compiled from service & troubleshooting documentation across every generator set that uses the Kohler KDI 2504TCR.
Service intervals
8| Item | Action | Hours | Months | Notes |
|---|
| oil | Change | 500 hr | | Minimum 500 hours oil change interval |
| Alternator V belt | Replace | | 36 mo | In case of low use: 36 months (Tab. 4.2 footnote 3) |
| Coolant | Replace | | 24 mo | In case of low use: 24 months (Tab. 4.2 footnote 4) |
| Engine oil | Change | | 12 mo | In case of low use: 12 months (Tab. 4.2 footnote 1) |
| Fuel filter cartridge | Replace | | 12 mo | In case of low use: 12 months (Tab. 4.2 footnote 1) |
| Oil filter cartridge | Replace | | 12 mo | In case of low use: 12 months (Tab. 4.2 footnote 1) |
| Paralleling box | Inspect | | 12 mo | Annually by a Kohler authorized distributor/dealer, or when wear, damage, deterioration, or malfunction is evident or suspected. |
| Paralleling box internal components | Inspect | | 1 mo | Monthly or when a condition noticed during external inspection may have affected internal components; enclosure cover must be removed by trained personnel. |
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
18| Type | Item | Value | Unit | Condition |
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| Clearance | Alternator standard belt deflection at point p | <10 | mm | approx. 10 kg force |
| Other | Alternator standard belt tension force | 350-450 | N | using DENSO BTG-2 or similar |
| Other | Engine speed adjustment | 50 | | default setting; settings between 40 and 60 acceptable; 52 increases speed by 2 RPM, 49 decreases by 1 RPM |
| Other | Generator to bus phase angle | -10 to 10 | degrees | verify with contactor closed |
| Other | Maximum inclination during operation | 30° max. 30 minutes | degree | even in combined |
| Other | Maximum inclination during operation | 35° max 1 minute | degree | |
| Other | Reactive droop | 1 | % | default setting; range 0.5 - 2% |
| Speed | Alternator Poly-V belt tension at point p | 149-196 | Hz | |
| Speed | Alternator standard belt tension at point p | 80-85 | Hz | |
| Torque | Alternator belt fastening bolts B and C | 40 | Nm | |
| Torque | Fuel filter cartridge | 17 | Nm | |
| Torque | Lifting screws/eyebolts | 25 | Nm | |
| Torque | Oil drain plug | 35 | Nm | |
| Torque | Oil filter cover | 25 | Nm | |
| Torque | PGEN terminal block connections | 0.5 | Nm | |
| Torque | PGEN terminal block connections | 4.4 | in. lbs. | |
| Torque | Water presence sensor | 5 | Nm | |
| Voltage | Controller measurement accuracy | 2 | % | without calibration; requires a calibrated multimeter for calibration |
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 | Ambient | Capacity | Notes |
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| Coolant | 50% ethylene glycol + 50% water or 50% propylene glycol + 50% water | BASF G05/G30/G33/G34/G40/G48/G50; VW G13/G12++; ARTECO XLC/XLI/LONG LIFE COOLANT/FREECOR SPC/FREECOR DSC; TEXACO AFC/XLC; REVKOGEL 2000; PARAFLU F02; CCI LLC L255A/LLC A432 | | | Antifreeze mixture |
| Engine oil | SAE 5W-30 / 10W-40 | API CJ4; ACEA E6-E9; Low S.A.P.S. | | 7.5 L | KDI 1903 TCR; max level including oil filter; standard version |
| Fuel | Diesel | EN 590; ASTM D975-09B; S15; No.1 or No.2 low sulfur or ultra low sulfur diesel | | | Biodiesel B10 max 10% methyl ester; do not use vegetable oil. For ambient below 0°C use suitable low-temperature fuel. |
| Fuel | No 1 Diesel (US) - ASTM D 975-09 B - Grade 1-D S 15 and No 2 Diesel (US) - ASTM D 975-09 B - Grade 2-D S 15, S 500 for mechanical models only | ASTM D 975-09 B | | | |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Procedures
12Alternator standard belt tension check and setting adjustment
⚠ Check belt tension only when engine is off.
Tools: DENSO BTG-2 or similar belt tension tool, torque wrench
- Check belt A condition; replace if worn out or deteriorated.
- Check at point p that tension is between 80 and 85 Hz.
- Using DENSO BTG-2 or similar tool F, check corresponding value is between 350 and 450 N.
- If no tool, apply approx. 10 kg force at point p; movement must be less than 10 mm.
- If not correct, loosen fastening bolts B and C.
- Pull alternator outwards in direction D to tension belt.
- Tighten bolts B and C in sequence with torque wrench E at 40 Nm.
- Check tension again; let engine run and cool, repeat adjustments if out of range.
Calibration adjustment
⚠ Copying personality profiles from one controller to another can overwrite calibration coefficients and requires re-calibration.
Tools: Calibrated multimeter with recent calibration verification
- Use a calibrated multimeter to measure the generator voltage and enter the correct value in the CONTROLLER CONFIG -> CALIBRATION screen.
- Use a calibrated multimeter to measure the bus voltage and enter the correct value in the CONTROLLER CONFIG -> CALIBRATION screen.
Verify Generator Operation diagnostic
⚠ Generators must all operate at the same frequency, voltage, and phase connection in order to parallel.
Tools: SiteTech software
- Ensure the load is not connected or is drawing less power than a single generator can provide.
- Navigate to CONTROLLER CONFIG -> COMMUNICATION SETUP and verify PGEN Nodes Online indicates the correct number of nodes.
- Verify alternator connection (voltage selector switch position), system voltage, and voltage regulator target on each generator.
- Start a single generator by pressing the Run button; the paralleling box contactor should close and the Generator Connected to Bus indicator should light.
- Verify bus and generator voltages match and generator to bus phase angle is between -10 and 10 degrees.
- Verify the load bus is energized and available at the load.
- Stop the generator by pressing the OFF button; the contactor should open.
- Repeat for each generator in the paralleling system.
Verify Paralleling and Load Sharing diagnostic
Tools: Load bank (optional)
- Place all generators in automatic mode by pressing the Auto button; verify the red shutdown indicator is not illuminated.
- Provide a local start request by holding AUTO, pressing RUN, releasing RUN, then releasing AUTO.
- Verify all generators start, one generator closes its contactor, and the others synchronize and close their contactors.
- Verify that the % of rated power of the generators matches, showing the generators are sharing load equally.
- If a load bank is available, test the system under load.
Control Harness Connections installation
⚠ The control harness connections for GEN 1 and GEN 2 must correspond to the source camlock cable connections.
- Connect the control harness from the generator set connected to the GEN 1 camlock connectors to GEN 1 CONTROL.
- Connect the control harness from the generator set connected to the GEN 2 camlock connectors to GEN 2 CONTROL.
- When not used, store the control harnesses on the storage rack inside the enclosure.
Grounding installation
⚠ Grounding electrical equipment: hazardous voltage can cause severe injury or death. Turn off the main circuit breakers of all power sources before servicing.
- Connect the ground lug on the paralleling box to earth ground according to applicable state and local codes.
- Follow NEC guidelines for grounding electrical equipment.
- The neutral is bonded to ground inside the paralleling box; if required, remove the bonding bus to disconnect neutral from ground.
Load Connections installation
⚠ Multiple power sources can automatically energize the distribution bus. Disconnect all power sources before connecting to the distribution bus.
- Remove the camlock security guard from one row of connectors for each generator and store the guard.
- Connect the load side ground (green) camlock cables to the distribution bus and then to the paralleling box.
- Connect the load side neutral (white) camlock cables to the distribution bus and then to the paralleling box.
- Connect the load side L1 (black), L2 (red), and L3 (blue) camlock cables to the distribution bus and then to the paralleling box.
Multiple Paralleling Boxes (PGEN Connections) installation
- Connect one or two generators to each paralleling box.
- Use Belden cable #9841 (or equivalent) shielded twisted-pair communication cable to connect the PGEN terminal blocks on the paralleling boxes.
- Tighten the connections to 0.5 Nm (4.4 in. lbs.).
Paralleling System Setup installation
⚠ Generator management must be disabled manually at each generator set controller.
Tools: Personal computer with SiteTech software
- Check that the voltage selector switch and/or alternator wiring matches the building voltage configuration for all generator sets.
- Set the digital output to Contactor (SiteTech Programmable Digital Output 116).
- Set reactive droop to 0.5-2% (default 1%), using the same reactive droop setting on all generators.
- Set the target voltage on all paralleled generators to the same value.
- Set engine speed adjustment to 50 on all generators (default 50; range 40-60).
- Verify metering; if voltage is incorrect, use the calibration procedure.
- Set Sync Mode in AUTO to ACTIVE and Sync Mode in Run to CHECK on all generators.
- Set Generator Management Enabled to OFF at each generator unless generator management is requested.
- Set up load management (load shed priorities) for non-critical loads.
- Stop all generators by pressing the OFF button on each controller.
Source Connections installation
⚠ Hazardous voltage. This equipment must be installed and serviced by qualified electrical personnel. Do not connect or disconnect cables under load.
- Remove the camlock security guard from one row of connectors for each generator and store the guard.
- Generator 2 connects to the upper set of camlocks; generator 1 connects to the lower set.
- Connect the source side ground (green) camlock cables to the paralleling box first and then to each generator.
- Connect the source side neutral (white) camlock cables to the paralleling box first and then to each generator.
- Connect the source side L1 (black), L2 (red), and L3 (blue) camlock cables to the paralleling box first and then to each generator.
Air filter cartridge replacement maintenance
- Release two fastenings F of cover A.
- Remove cartridges B and G.
- Reinstall new cartridges B and G.
- Reinstall cover A and check right tightness of fastenings F.
Air filter check maintenance
⚠ Do not use compressed air.
Tools: damp cloth
- Release two clasps F of cover A.
- Remove cartridges B and G.
- Remove cap C.
- Clean inside components A, C, and D with a damp cloth.
- Do not use compressed air; repeatedly tap front side E on a flat surface.
- When cartridge G is dirty, do not clean it but replace cartridges B and G.
- Reinstall cartridges G and B, cap C, and cover A; check clasps F tightness.
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 Kohler KDI2504 family
14| Part # | Description | Category |
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| A-226955 | Air cleaner assembly | Air filter |
| GM16944 | Element, air cleaner | Air filter |
| GM66601 | Element, Inner | Air filter |
| 8972824032 | Acid charge Pb-Ca maintenance free, 12V - 1100 CCA | Battery |
| 8972824033 | Acid charge Pb-Ca maintenance free, 12V - 1100 CCA | Battery |
| ED0082051350-S | COV.HEAD GASK.-OR SET 2504 TCR | Gasket |
| ED0082051370-S | COV.HEAD GASK.-OR SET 2504 M | Gasket |
| GM22310 | Hose, Reducer | Hose |
| GM86224 | Hose, Air Intake (Item 5) | Hose |
| GM92268 | Bracket, air cleaner Mtg. | Mounting |
| GM95611 | Bracket, Air Cleaner Mtg. | Mounting |
| ED0053029490 | 2.5 Blue smoke | Service part / kit |
| M125A-08-80 | Washer, Plain 8.4 ID x 16.0 OD | Service part / kit |
| 273377 | Gauge, restriction | Sensor |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
Aftermarket parts that fit this engine
15Parts listed by aftermarket suppliers as fitting this engine — leads compiled from supplier catalogs; verify the exact part for your serial number.
Also used in
3- Jcb 407 — Loader Wheeled
- Jcb 525-60 HI VIZ — Telehandler
- Merlo TF27.6 — Telehandler
Other equipment known to use this engine, via filter-application cross-reference — useful for sourcing parts even when your exact machine isn't listed elsewhere on this page.
Common questions
What is the oil capacity of the Kohler KDI 2504TCR?
The Kohler KDI 2504TCR engine has an oil capacity of 11.5 liters.
What is the displacement of the Kohler KDI 2504TCR?
The Kohler KDI 2504TCR has a displacement of 2.482 liters with 4 cylinders.
Which generators use the Kohler KDI 2504TCR engine?
The Kohler KDI 2504TCR powers 2 generator set(s), including Kohler 45 REOZT4, Kohler KDI 2504 TCR.
What is a common problem with the Kohler KDI 2504TCR engine?
A commonly reported issue on generators using the Kohler KDI 2504TCR is: Warning YELLOW light turn on. Cause: Engine ECU has detect a malfunctions. Fix: Contact REHLKO authorised workshops.