Kohler KDI 1903M Instruction manual

KDI 1903M
KDI 2504M
WORKSHOP MANUAL
TP-6939 3/23

INDEX
EN
REGISTRATION OF MODIFICATIONS TO THE DOCUMENT
Any modifications to this document must be registered by the drafting body, by completing the
following table.
Released by Document code Revision Issue date Review date Edited by Endorsed
Technical
Documentation ED0053029610 9.6 04/201303/2023 M. SILVESTRONE V. MANINI
Translated from the original manual in Italian language.
Data reported in this issue can be modified at any time by KOHLER.

INDEX
EN
1General information...............................................................................................................8
1.1 Useful information ........................................................................................................................... 8
1.2 Manufacturer and engine identification ....................................................................................... 9
1.3 Identification of the main internal components of the engine and operating reference
(BASE CONFIGURATION) ............................................................................................................................. 10
1.4 Identification of the external components of the engine (BASE CONFIGURATION)............. 12
2Technical information.......................................................................................................... 15
2.1 Engine specifications .................................................................................................................... 15
2.2 Engine dimensions (mm) .............................................................................................................. 17
2.3 Performance................................................................................................................................... 18
2.4 Oil .................................................................................................................................................... 19
2.5 Fuel.................................................................................................................................................. 20
2.6 Coolant recommendation ............................................................................................................. 22
2.7 Battery recommendations ............................................................................................................ 23
2.8 Periodic maintenance ................................................................................................................... 23
2.9 Fuel system .................................................................................................................................... 25
2.10 Lubrication circuit.......................................................................................................................... 29
2.11 Coolant circuit................................................................................................................................ 32
2.12 Intake and exhaust circuit ............................................................................................................ 33
2.13 Electric system............................................................................................................................... 35
2.14 Sensors and switches ................................................................................................................... 38
2.15 Electrical components .................................................................................................................. 40
2.16 Timing system and tappets .......................................................................................................... 44
2.17 Components handling................................................................................................................... 47
2.18 Balancer device (optional) ............................................................................................................ 48
3Safety information ............................................................................................................... 49
3.1 Before start-up .............................................................................................................................. 49
3.2 Safety precautions ........................................................................................................................ 49
3.3 General remarks ............................................................................................................................ 49
3.4 Safety signal description .............................................................................................................. 52
3.5 Information and safety signals..................................................................................................... 53
3.6 Safety and environmental impact................................................................................................ 55
3.7 Location of safety signals on engine........................................................................................... 55
4Storage information............................................................................................................. 56
4.1 Product preservation..................................................................................................................... 56
4.2 Engine storage (up to 6 months).................................................................................................. 56
4.3 Engine storage (over 6 months) ................................................................................................... 56
4.4 Engine starting after storage ....................................................................................................... 57

INDEX
EN
5Information regarding discharge of liquids ....................................................................... 58
5.1 Coolant ........................................................................................................................................... 58
5.2 Engine oil........................................................................................................................................ 59
6Information for replacing the functional units ................................................................... 60
6.1 Injectors and injection pump replacement ................................................................................. 60
6.2 Coolant pump replacement.......................................................................................................... 68
6.3 Replace the crankshaft pulley...................................................................................................... 69
6.4 Oil pump replacement................................................................................................................... 70
6.5 Oil pressure valve replacement.................................................................................................... 73
6.6 Oil filter replacement..................................................................................................................... 74
6.7 Fuel filter replacement .................................................................................................................. 74
7Information for disassembly ............................................................................................... 76
7.1 Recommendations for disassembly ............................................................................................ 76
7.2 Electric components disassembly ............................................................................................... 76
7.3 Exhaust manifold disassembly..................................................................................................... 78
7.4 Coolant recirculation components disassembly ........................................................................ 78
7.5 Crankshaft pulley disassembly .................................................................................................... 79
7.6 Lubrication circuit disassembly ................................................................................................... 79
7.7 Intake manifold disassembly........................................................................................................ 81
7.8 Fuel system disassembly .............................................................................................................. 81
7.9 Timing system gear disassembly................................................................................................. 84
7.10 Flange unit disassembly ............................................................................................................... 84
7.11 Cylinder head unit disassembly ................................................................................................... 85
7.12 Oil sump unit disassembly............................................................................................................ 88
7.13 Engine block disassembly ............................................................................................................ 88
8Information about overhauling ........................................................................................... 94
8.1 Recommendations for overhauls and tuning ............................................................................. 94
8.2 Crankcase....................................................................................................................................... 94
8.3 Tappets and tappet housings....................................................................................................... 99
8.4 Crankshaft.................................................................................................................................... 100
8.5 Connecting rod - piston assembly............................................................................................. 101
8.6 Cylinder head ............................................................................................................................... 105
8.7 Oil pump check ............................................................................................................................ 108
9Assembly information ....................................................................................................... 110
9.1 Information on engine configuration......................................................................................... 110
9.2 Assembly recommendations ...................................................................................................... 110
9.3 Engine block assembly ............................................................................................................... 111
9.4 Oil sump unit assembly............................................................................................................... 117
9.5 Flange unit assembly .................................................................................................................. 119

INDEX
EN
9.6 Timing system gear assembly and injection pump.................................................................. 120
9.7 Cylinder head unit assembly ...................................................................................................... 122
9.8 Fuel system assembly ................................................................................................................. 128
9.9 Intake manifold assembly ........................................................................................................... 130
9.10 Exhaust manifold assembly........................................................................................................ 131
9.11 Lubrication circuit assembly ...................................................................................................... 131
9.12 Crankshaft pulley assembly ....................................................................................................... 133
9.13 Coolant circuit assembly ............................................................................................................ 134
9.14 Electric component assembly .................................................................................................... 134
9.15 Tightening torques and the use of sealants............................................................................. 136
10 Fluids filling information ................................................................................................... 142
10.1 Engine oil...................................................................................................................................... 142
10.2 Coolant ......................................................................................................................................... 142
11 Information about optional components.......................................................................... 145
11.1 Oil dipstick in cylinder head ....................................................................................................... 145
11.2 Heater (replacement) .................................................................................................................. 146
11.3 Poly-V alternator belt (replacement and adjustment) ............................................................. 147
11.4 Tightening pulley and alternator for Poly-V belt ...................................................................... 148
11.5 Idler gear (for 3rd / 4th PTO) ...................................................................................................... 151
11.6 3rd PTO (replacement) ................................................................................................................ 152
11.7 4th PTO (replacement) ................................................................................................................ 155
11.8 3rd + 4th PTO (configurations) ................................................................................................... 158
11.9 Balancer device (replacement)................................................................................................... 158
11.10 Air filter (cartridge replacement)................................................................................................ 162
11.11 Remote oil filter (disassembly and assembly) .......................................................................... 162
11.12 Intake circuit (replacement) ....................................................................................................... 164
11.13 Muffler (replacement).................................................................................................................. 165
11.14 Cooling circuit (replacement) ..................................................................................................... 166
11.15 Engine feet (information) ............................................................................................................ 169
11.16 Oil sump with supporting structure........................................................................................... 170
11.17 Oil sump 15L................................................................................................................................. 173
11.18 Crankcase oil filter - Lengthwise assembly.............................................................................. 175
12 Information on adjustments.............................................................................................. 177
12.1 Air filter check.............................................................................................................................. 177
12.2 Rubber hose and manifold control ............................................................................................ 177
12.3 Oil leak check............................................................................................................................... 178
12.4 Oil pressure check....................................................................................................................... 178
13 Tools information............................................................................................................... 180
13.1 Information regarding specific tools ......................................................................................... 180

INDEX
EN
14 Information about failures ................................................................................................. 182
14.1 Possible causes and trouble shooting ...................................................................................... 182
15 Glossary ............................................................................................................................. 184
15.1 Glossary ........................................................................................................................................ 184

GENERAL INFORMATION 1
7 EN

1GENERAL INFORMATION
EN 8
1GENERAL INFORMATION
1.1 Useful information
•This manual contains the instructions needed to carry out proper use and maintenance of the engine,
therefore it must always be available, for future reference when required.
•The information, descriptions and illustrations contained in this manual reflect the basic configuration
of the engines (Par. 1.3 and Par. 1.4).
•However, the development of engines is continuous. Therefore, the information in this manual is
subject to change without notice.
•KOHLER reserves the right to make, at any time, changes on the engines for technical or commercial
reasons.
•These changes do not require KOHLER to intervene on the production marketed up to that time and
nor to consider this manual as inappropriate.
The paragraphs, tables and figures are numbered by chapter and followed by the progressive paragraph,
table and/or figure number.
Es: Par. 1.3 - chapter 1paragraph 3.
Tab. 2.4 - chapter 2table 4.
Fig. 4.5 - chapter 4figure 5.
NOTE: The paragraphs may contain sub-paragraphs.
•All technical terms, specific components and symbols (Tab. 15.1) that are in the manual are listed and
described inside the glossary, which can be consulted in (Chap. 15).
•The references of the objects described in the text and in the figure are indicated by letters and
numbers, which are always and only related to the paragraph you are reading unless there are specific
references to other figures or paragraphs.
•Reference to values are indicated by letters or numbers (underlined).
•Any additional section that KOHLER will deem necessary to supply at a later stage must be kept with
the manual and considered as an integral part of it.
•The information contained in this manual is the sole property of KOHLER, therefore no partial or total
reproduction or replication is allowed without the express permission of KOHLER.
1.1.1 Useful Information -accident prevention -environmental impact
•Before proceeding repair - handling the engine, you should read Chap. 3in its entirity, which contains
important information regarding procedures to follow with regard to safety and the environment.

GENERAL INFORMATION 1
9 EN
1.2 Manufacturer and engine identification
The engine identification name plate is situated in the lower part of the crankcase; it is visible from the
intake or exhaust side.
Fig 1.1 -Fig 1.2
Fig 1.3

1GENERAL INFORMATION
EN 10
1.3 Identification of the main internal components of the engine and operating reference
(BASE CONFIGURATION)
VIEW OF EXHAUST SIDE
Fig 1.4
The following chapters contain operating
references in order to clearly understand the
engine. This paragraph illustrates these
references that may be recognised by means
of some main internal components.
Should you need to execute complex
operations, always consult this paragraph.
NOTE: it is advisable to keep this page
visible during disassembly and assembly
operations.
Tab 1.1
REF.
DESCRIPTION
A
View of timing system side (2 nd PTO)
B View of flywheel side (1 st PTO)
C
View of exhaust side
D
View of intake side
1
Cylinder/Piston N. 1 (KDI 1903 - KDI 2504)
2
Cylinder/Piston N. 2 (KDI 1903 - KDI 2504)
3
Cylinder/Piston N. 3 (KDI 1903 - KDI 2504)
4
Cylinder/Piston N. 4 (KDI 2504)
POS.
DESCRIPTION
5
Crankshaft pulley (2 nd PTO)
6
Gear timing system
7
Thermostatic valve
8
Oil pump
9
Oil suction hose
10
Crankshaft
11
Exhaust manifold
12
Intake manifold

GENERAL INFORMATION 1
11 EN
13
Camshaft
14
Gears adaptor for 3
a
/4
a
PTO (optional)
15
Flywheel (1
st
PTO)
16
Injector
VIEW OF FLYWHEEL SIDE
Fig 1.5
VIEW OF TIMING SYSTEM SIDE
Fig 1.6

1GENERAL INFORMATION
EN 12
1.4 Identification of the external components of the engine (BASE CONFIGURATION)
VIEW OF TIMING SYSTEM SIDE - EXHAUST
Fig 1.7
VIEW OF FLYWHEEL SIDE
Fig 1.8

GENERAL INFORMATION 1
13 EN
This paragraph illustrates all external components
that are present in the base configuration of the
engine.
For components present on engines that differ
from those represented in these illustrations, refer
to Chap. 11.
NOTE: The illustrated components may differ
from those illustrated; the illustration is only as an
example.
Tab 1.2
POS.
DESCRIPTION
1
Oil filler cap
2
Oil pressure switch
3
Starter motor
4
Oil drain plug
5
Engine identification name plate
6
Alternator
7
Coolant pump
8
Coolant temperature sensor
9
Oil filler cap side
10
Thermostatic valve
11
High-pressure fuel injection pump
12
Lub. oil filter
13
Oil dipstick
14
Fuel filter
15
Crankshaft pulley (2 nd PTO)
16
Flywheel (1
st
PTO)
17
Intake manifold
POS.
DESCRIPTION
18
Exhaust manifold
19
Flange bell
20
Injectors

1GENERAL INFORMATION
EN 14
UPPER VIEW
Fig 1.9

TECHNICAL INFORMATION 2
15 EN
2TECHNICAL INFORMATION
2.1 Engine specifications
MANUFACTURER SPECIFICATIONS AND OPERATION
GENERAL INFORMATION
UNIT OF
MEASURE
KDI 1903 M KDI 2504 M
Operating cycle
diesel - 4 stroke
Cylinders
N°
3
4
Bore x stroke
mm
88x102
Displacement
cm 3
1861
2482
Compression ratio
18.4:1
Intake
Atmospheric pressure
Cooling Liquid
Crankshaft rotation (view from flywheel side) Counterclockwise
Combustion sequence
1-3-2
1-3-4-2
Timing System
Valves per cylinder
N°
4
Timing System
Rods and rocker arms - Camshaft in
the crankcase
Tappets Hydraulic
Injection Direct
Engine dry weight
Kg
210
244
MAX inclination 30' continuous operation
(min./a)
25°
MAX inclination 1' continuous operation
(min./a)
35°
Volume of aspirated air (2600 rpm)
Kg/h
2.2
2.9
POWER AND TORQUE
GENERAL INFORMATION
UNIT OF
MEASURE
KDI 1903 M KDI 2504 M
MAX operating speed
Rpm
2600
MAX operating power (ISO TR 14396 - SAE
J1995 - CE 97/68)
kW 31 41
Maximum torque (at 1500 rpm)
Nm
133
170
Admissible axial load on crankshaft
Kg
300
CONSUMPTIONS
GENERAL INFORMATION
UNIT OF
MEASURE
KDI 1903 M KDI 2504 M
Specific fuel consumption (best point)
g/kWh
210
Oil consumption
%Fuel
< 0.05
FUEL SUPPLY SYSTEM
GENERAL INFORMATION
UNIT OF
MEASURE
KDI 1903 M KDI 2504 M

2TECHNICAL INFORMATION
EN 16
Type of fuel Diesel UNI-EN590 - ASTM D975
High-pressure fuel injection pump STANADYNE - DB
Fuel supply Low pressure electric pump
Fuel filter
Filtering surface
cm 2
2300
Degree of filtration
µm
5
Maximum pressure at injection pump inlet
bar
< 0.5
LUBRICATION CIRCUIT
GENERAL INFORMATION
UNIT OF
MEASURE
KDI 1903 M KDI 2504 M
Fuel
Lubrication
See Par. 2.4
Circuit forced
Lobe pump
Oil sump capacity (MAX)
Lt.
8.9
11,5
Oil pressure switch
Intervention pressure (MIN)
bar
0.8±0.1
Oil filter
Maximum operating pressure
bar
7.0
Degree of filtration
µm
17±2
Filtering surface
cm 2
1744
COOLING CIRCUIT
GENERAL INFORMATION
UNIT OF
MEASURE
KDI 1903 M KDI 2504 M
Coolant
%
See Par. 2.6
Water pump
Lt./min
75
Thermostatic valve
Opening temperature
°C
+79
Stroke at 91°C
mm
7.50
Liquid recirculation
Lt./h
9
ELECTRICAL SYSTEM - ELECTRIC FAN
GENERAL INFORMATION
UNIT OF
MEASURE
KDI 1903 M KDI 2504 M
Circuit rated voltage
V
12
External alternator (rated current)
A
80
Starter motor power
kW
2
System electrical consumption, excluding:
heater, electric pump, electric fan, starter
motor
W24
Coolant temperature indicator light
Indicator light operating temperature
°C
+100/+110

TECHNICAL INFORMATION 2
17 EN
2.2 Engine dimensions (mm)
NOTE: Dimensions vary according to engine configuration.
Fig 2.1

2TECHNICAL INFORMATION
EN 18
2.3 Performance
Fig. 2.2
N= Automotive rating curve
MN = Torque curve
C= Specific fuel consumption curve
NOTE: Refer to KOHLER for power curves, torque curves and specific consumptions at speeds
other than those given above.

TECHNICAL INFORMATION 2
19 EN
Key
•N (ISO TR 14396 - SAE J1995 - CE 97/68) AUTOMOTIVE RATING CURVE: Intermittent duty at
variable speed and load. Engine capacity at intermittent conditions with variable speed and load.
•MN: = TORQUE RATING CURVE: Also called twisting moment, it is the push generated by the
engine through transmission. The highest engine performance is obtained at the maximum torque.
•C= SPECIFIC CONSUMPTION CURVE: Engine fuel consumption in a given time at a certain
revolution value. Expressed in g/kW (grams/kilowatt), it expresses fuel yield.
* The above curves express indicative values, in that the overall performance depends on the type of
application and the ECU control uni.
•The ratings reported in the diagram regard the run-in engine, fitted with air and exhaust filters, at
the atmospheric pressure of 1 Bar and at a room temperature of +20°C
•Maximum rating is guaranteed with a 5% tolerance.
Warning
•Non approval by KOHLER for any modification releases the company from liability for damage
incurred on the engine.
2.4 Oil
Important
•The engine may be damaged if operated with improper oil level.
•Do not exceed the MAX level because a sudden increase in engine rpm could be caused by its
combustion.
•Use only the recommended oil to ensure adequate protection, efficiency and service life of the engine.
•The use of lubricants other than recommended may shorten the engine life.
•Viscosity must be appropriate to the ambient temperature to which the engine is to be exposed.
Danger
•Prolonged skin contact with the exhausted engine oil can cause cancer of the skin.
•If contact with oil cannot be avoided, thoroughly wash your hands with soap and water as soon as
possible.
•For the exhausted oil disposal, refer to the Par. DISPOSAL and SCRAPPING.
2.4.1 SAE oil classification
•In the SAE classification, oils are identified according to viscosity without considering any other
qualitative characteristic.
•The code is composed of two numbers, which indicate, and must correspond to, the ambient
temperature in which the engine operates, the first number refers to the viscosity when cold, for use
during winter (" W"), while the second number is for viscosity at high temperatures.
2.2

2TECHNICAL INFORMATION
EN 20
RECCOMENDED OIL
VISCOSITY SAE
10w-30 (-25°C ÷ +40°C)
10w-40 (-25°C ÷ +50°C)
5w-30 (-30°C ÷ +40°C)
0w-40 (-40°C ÷ +50°C)
WITH SPECIFICATIONS
API
CI-4 Plus CI-4
CH-4
ACEA
E7
E5
•Low S.A.P.S. oils, sulfate ashes <1% may not be used with fuels with a sulfur content >50ppm.
•Filtration of oils is critical to proper operation and lubrication; always change filters regularly as
specified in this manual.
2.5 Fuel
Important
•Use of other types of fuel could damage the engine. Do not use dirty diesel fuel or mixtures of diesel
fuel and water since this will cause serious engine faults.
•Any failures resulting from the use of fuels other than recommended will not be warranted.
Warning
•Clean fuel prevents the fuel injectors from clogging. Immediately clean up any spillage during
refuelling.
•Never store diesel fuel in galvanized containers (i.e. coated with zinc). Diesel fuel and the galvanized
coating react chemically to each other, producing flaking that quickly clogs filters or causes fuel pump
and/or injector failure.
2.3
FUEL COMPATIBILITY
EN 590 (biodiesel content max. 7% (V/V))
ASTM D 975 Grade 1-D S15
ASTM D 975 Grade 2-D S15
NATO F-54, equivalent to diesel fuel in accordance with EN 590
EN 590 or ASTM D 975 Grade 1, 2 -D S15 Arctic Diesel
JIS K 2204 No. 1, No. 2
NOTE: In a warranty case the customer must prove by a certificate from the fuel supplier that an allowed
fuel was used.
KDI Mechanical Injection Tier 3,Tier 4 Final – Stage IIIA, Stage IIIB, Stage V certified Engines (w and
w/o EGR)
•Those engines are designed for fuels in accordance with EN 590 and ASTM D975 for a cetane number
of at least 45. Since those engines are not equipped with exhaust gas after-treatment, they can be
operated with diesel fuels with sulfur content up to 500 mg/kg (ppm). Compliance with the emission
requirements is guaranteed only with sulfur content up to 15 mg/kg (ppm).
Engines operated with fuels as per EN 590 and ASTM D975 with sulfur content < 15mg/kg have an oil
changing interval of 500hrs. Fuels with a sulfur content > 500 mg/kg demand a shorter lubricating oil