Service Manual
4TNV98 & 4TNE98 Diesel Engine
D20S-5, D25S-5, D30S-5, D33S-5, D35C-5
(4TNV98 : EM0Q3, EM0Q4, EM0Q5)
D20S-5, D25S-5, D30S-5, D33S-5, D35C-5
(4TNE98 : EM0QC, EM0QD, EM0QE)
D20G, D25G, D30G
(4TNE98)
SB4319E00
Jan. 2008
1
Important Safet y Information
Most accidents involvi ng product operation, maintenance and repair ar e caused by failure to observe basic
safety rules or precaut ions. An ac cident can often be avoided by recognizing pot entially hazardous situati ons
before an accident occurs. A person must be alert t o potenti al hazards. This person should also hav e the
necessary training, skills and tools to perf orm these functions properly.
Read and understand all safety precautions and warnings before op erat in g o r performing lubrication,
maintenance and repair on this product.
Basic safety precautions are listed in the “Saf ety” section of the Service or Technical Manual. Additional safety
precautions are li sted in the “Safety” section of the owner/oper ation/maint enanc e publication.
Specific safety warnings f or all these publi cati ons are provi ded i n the descri pti on of oper ations where hazards
exist. WARNING labels have also been put on the product to provide instructions and to identify specific
hazards. If these hazard warnings are not heeded, bodily injury or death could occur to you or other persons.
Warnings in this publication and on t he pr oduc t labels are identified by the f ollowing symbol.
WARNING
Improper operation, lubrication, maintenance or repair of this product can be dangerous and could
result in in jur y or de a t h.
Do not operate or perform an y lubrication, main tenance or repair on this product, until you have read
and understood the operation, lubrication, maintenance and repair information.
Operations that may c ause product damage are identified by NOTICE l abels on the pr oduc t and in this
publication.
DOOSAN cannot antici pate every possible circumstance that might involve a potential hazard. The warnings
in this publication and on the product are therefore not all inclusive. If a tool, procedure, work method or
operating tec hnique not specifically recommended by DOO SAN is used, you must satisfy yourself that it is
safe for you and others. You should also ensure that the product will not be damaged or made unsaf e by the
operation, lubr ic ation, maintenance or r epair procedur es you c hoose.
The information, specifica tions, and illustrations in this publication are on the basis o f information available at the
time it was written. The specifications, torques, pressures, measurements, adjustments, illustrations, and other
items can change at any time. These changes can affect the service given to the product. Obtain the complete and
most current information before starting any job. DOOSAN dealers have the most current information available.
4TNV98 & 4TNE98 Diesel Engine 3 Index
Section 1. GENERAL SERVICE
INFORMATION
Component Identif ication ......................................7
Location of Labels.................................................8
Engine Nameplate (Typical)......................8
Emission Control Regulations ...............................8
EPA / ARB Regulations - USA Only...........8
Emission Control Labels .......................................9
The 97/68/EC Directive Certified Engines..............9
Engine Family.......................................................9
Function of Major Engine Components................10
Function of Cooling System Components............11
Diesel Fuel..........................................................12
Diesel Fuel Specifications.......................12
Filling The Fuel T ank..............................13
Priming the Fuel System.........................15
Engine Oil...........................................................16
Engine Oil Specifications........................16
Engine Oil Viscosity................................16
Checking Engine Oil...............................17
Adding Engine Oil...................................17
Engine Oil Capacity (Typical)..................17
Engine Coolant...................................................18
Engine Coolant Specifications ................19
Filling Radiator with Engine Coolant .......19
Engine Coolant Capacity (Typical)..........20
Specifications......................................................20
Description of Model Num ber .................20
Engine General Specifications................21
Principal Engine Specifications............................22
4TNV98 EPA Tier 2 ..............................22
4TNE98 EPA Tier 3 ..............................23
Engine Service Standards...................................24
Tightening Torques for Standard Bolts and Nuts..25
Abbreviations and Sym bols .................................27
Abbreviations.........................................27
Symbols.................................................27
Unit Conversions................................................28
Unit Pre fi xes...........................................28
Units of Length.......................................28
Units of Volume......................................28
Units of Mass.........................................28
Units of Force.........................................28
Units of Torque.......................................28
Units of Pressure....................................28
Units of Power........................................28
Units of Temperature..............................28
Section 2. PERIODIC MAINTENANCE
Before You Beg in Se rvicing ................................ 29
Introduction ........................................................ 40
The Importance of Periodic Maintenance 40
Performing Periodic Maintenance........... 40
Yanmar Replacement Parts.................... 40
Required EPA / ARB Maintenance-USA Only
.............................................................. 40
EPA / ARB Installation Requirements-USA
Only....................................................... 40
Periodic Maint enanc e S c hedule.......................... 41
Periodic Maint enanc e P r oc edur es ...................... 43
Drain Fue l F il te r / Water Sepa r a to r......... 43
4TNE98 For D25S-5 Only...................... 43
Daily................................................................... 45
After Initial 50 Hours of Operation...........45
Every 50 Hours of Operation .................. 48
Every 250 Hours of Operation................51
Every 500 Hours of Operation................54
Every 1000 Hours of Operation..............59
Every 1500 Hours of Operation..............61
Every 2000 Hours of Operation..............62
Section 3. ENGINE
Before You Beg in Se rvicing ................................ 63
Introduction ........................................................ 66
Cylinder Head Specifications .............................. 66
Adjustment Specifications......................66
Cylinder Head........................................66
Intake / Exhaust Valve and Guide Cont... 67
Push Rod............................................... 68
Rocker Arm and Shaft............................ 68
V a l ve Spring........................................... 68
Camshaft and Timing Gear Train Specifications.. 68
Camshaft............................................... 68
Idler Gear Shaft and Bushing ................. 69
Tim ing Ge a r Backlash............................ 69
Crankshaft and Piston Specificati ons .................. 70
Crankshaft............................................. 70
Thrust Bearing.......................................70
Piston....................................................71
Connecting Rod ..................................... 72
Tappet.................................................... 72
Cylinder Block Specificati ons .............................. 73
Cylinder Block........................................ 73
Special Torque Chart .......................................... 73
Torque for Bolts and Nuts.......................73
Special Service Tools.......................................... 75
4TNV98 & 4TNE98 Diesel Engine 4 Index
Measuring Instruments........................................77
Cylinder Head.....................................................80
Cylinder Head Com ponents....................80
Disassembly of 4-Valve Cylinder Head ...82
4TNE98 Engine......................................87
Disassembly of Cylinder Head................89
Cleaning of Cyli nder Head Com ponents .92
Inspection of Cyli nder Head Com ponents93
Reassembly of Cylinder Head ................98
Measuring and Adjusting Valve Clearance.........104
4TNE98 Engine....................................105
4TNV98 Engine....................................106
Crankshaft and Camshaft Components.............109
Disassembly of Engine..........................111
Disassembly of Camshaft and Timing
Components..........................................111
Disassembly of Crank shaft and Piston
Components......................................... 116
Inspection of Cr ank shaft and Camshaft
Components.........................................120
Honing and Boring................................126
Reassembly of Crankshaft and Piston
Components.........................................127
Reassembly of Camshaft and Timing
Components.........................................136
Final Reassembly of Engine.................138
Section 4. FUEL SYSTEM
Before You Beg in Se rvicing...............................139
4TNV98 ENGINE..............................................141
Introduction .......................................... 141
Fuel Injec tion Pump..............................141
Stop Solenoid.......................................142
Cold Start Device..................................142
Trochoid Fuel Pump.............................142
Fuel Sys te m Specifica t io n s...............................143
Special Torque Chart ............................143
Test and Adjustment Specifications.......144
Special Service Tools........................................145
Measuring Instruments......................................145
Fuel Sys te m D ia g ra m.......................................146
Fuel System Components................................. 147
4-Valve Cylinder Head..........................147
Fuel Injec tion Pump..........................................148
Removal of Fuel Injection Pump...........148
Installation of Fuel Injection Pump........152
Checking and Adjusting Fuel Injection Timing....157
Determining t he Fuel I njec tion Timing
Specification......................................... 157
Checkin g Fuel Injection Timing............. 158
Adjustin g Fu e l Inje ction Ti min g............. 161
Fuel Injec to r s....................................................163
Removal of Fuel Injectors..................... 163
Testing o f Fue l Inje ctors....................... 164
Disassembly and Inspection of Fuel
Injectors............................................... 165
Adjustin g Fu e l Inje ctor Pressure........... 166
Reassembly of Fuel Injectors............... 167
Installation of the Fuel Injectors............ 167
4TNE98 ENGINE..............................................168
Fuel System Special Torque Chart........ 168
Measuring Instruments......................... 168
Fuel System Components.................... 169
Fuel System Components.................... 170
Structure And Operation Of Fuel Injection
Pump ................................................... 171
Overview.............................................. 172
Plunger Operation................................ 175
Process................................................ 176
Reverse Rotation Pr ev ention Mechanism
............................................................ 178
Fuel Injection Volume Adjustment
Mechanism .......................................... 178
Delivery Valve Assembly...................... 179
Delivery Valve Holder with Damping Valve
............................................................ 179
A
ll - Speed Governor........................................ 180
At Start of Engine................................. 182
During Idling......................................... 183
At Full-Load Maxim um Speed Control .. 184
At No-Load Maximum Speed Control ... 185
Full-Load Position Adjustment Mechanism
............................................................ 186
Stru c tu re And Ope r a tion Of Timer..................... 187
Standard Type Au to matic Timer............ 187
Magnetic Valve (Stop Solenoid)............ 188
Remova l O f Fue l In jec t io n Pu mp....................... 189
Installation Of The Fuel Injection Pump............. 192
Checking / Adjustment Of Fuel Injection Timing. 194
Servicin g Th e Fu e l In jec to rs.............................. 196
Removal of the Fuel Injectors............... 196
Inspection and Testing of the Fuel Injectors
............................................................ 197
Judgement Criteria on Atomization
Condition ............................................. 199
Installation of Fuel Injectors.................. 200
4TNV98 & 4TNE98 Diesel Engine 5 Index
Sectio n 5. COOLING SYSTEM
Before You Beg in Se rvicing...............................201
Introduction.......................................................203
Cooling System Diagram ..................................203
Engine Coolant Pump Com ponents...................204
Engine Coolant System Check..........................205
Engine Coolant Pump.......................................205
Removal of Engine Coolant Pump........205
Disassembly of Engine Coolant Pump..207
Cleaning and Inspect ion.......................207
Reassembly of Engine Coolant Pump... 208
Installation of Engine Coolant Pump.....208
Section 6. LUBRICATION SYSTEM
Before You Beg in Se rvicing...............................210
Introduction.......................................................212
Oil Pump Service Information............................212
Lubrication Sy stem Diagr am .............................214
Checking Engine Oil Pressure...........................215
Trochoid Oil Pump............................................215
Oil Pump Components .........................215
Disassembly of Oil Pump......................216
Cleaning and Inspect ion.......................216
Reassembly of Oil Pump......................217
Section 7. STARTER MOTOR
Before You Beg in Se rvicing...............................219
Introduction.......................................................221
Starter Motor Information...................................221
Starter Motor Specifications...............................222
Starter Motor Troubleshooting...........................223
Starter Motor Components................................224
Starter Motor.....................................................225
Removal of Starter Motor......................225
Disassembly of Starter Motor................225
Cleaning and Inspect ion.......................227
Reassembly of Starter Motor ................232
Check Pinion Projec tion Length............233
No-Load Test........................................234
Installation of Starter Motor...................234
Section 8. TROUBLESHOOTING
Special Service Tools .......................................235
Troubleshooting By Measuring Compression
Pressure...........................................................236
Compression Pressure Measurement
Method................................................ 236
Quick Reference Table For Troubleshooting..... 239
Troubleshooting Charts..................................... 240
Wiring Diagram................................................. 243
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 7
Section 1. GENERAL SERVICE INFORMATION
Component Identification
Figure 4-1a, Figure 4- 1b shows where the major
engine components are locat ed.
4TNV98 ENGINE
Figure 4-1a
(1) Lifting Eye (Flywheel End).
(3) Lifting Eye (Engine Cooling Fan End).
(4) Engine Coolant Pump. (5) Engine Cooling Fan.
(6) Crankshaft V-Pulley. (7) V-Belt.
(8) Side Filler Port (Engine Oil). (9) Drain Plug (Engine Oil).
(10) Fuel Injection Pump. (12) Engine Oil Filter.
(13) Dipstick (Engine Oil) (14) Governor Lever.
(15) Intake Manifold. (16) Fuel Filter.
(17) Fuel Inlet. (18) Fuel Return to Fuel T ank.
(19) Top Filler Port (Engine Oil). (20) Rocker Arm Cover.
(21) Air Intake Port (From Air Cleaner).
(22) Flywheel. (23)Starter Motor.
(24) Exhaust Manifold. (25) Alternator.
4TNE98 ENGINE
Figure 4-1b
(1) Fuel Filter / Water Separator
(2)Top Filler Port (Engine Oil)
(3) Governor Lever
(4) Fuel Injection Pump
(5) Side Filler Port (Engine Oil)
(6) Fuel Priming Pump
(7) Drain Plug (Engine Oil)
(8) Engine Oil Filter
(9) Dipstick (EngineOil)
(10) Engine Coolant Pump
(11)
Alternator
(12) Glow Plug
(13) V-Belt
(14) Crankshaft V-Pulley
(15) Starter Motor
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 8
Locatio n of L ab els
Figure 4-2 shows the location of regulatory and
safety label s on Yanmar TNV & TNE series engines.
4TNE98 ENGINE
4TNV98 ENGINE
Figure 4-2
The typical locati on of the emission control
information label shown (Fi gure 4-2 (2), (3)).
The typical locati on of the engine nameplate is
shown (Figure 4-2 (1), (4)).
Engine Nameplate (Typical)
Emission Control Regulations
EPA / ARB Regulati ons - USA Only
Yanmar engines meet Environmental Protecti on
Agency (EPA) (U. S. Federal) emission control
standards as well as the Califor nia Air Resources
Board (ARB, Calif or nia) r egulations. Only engines
that conform to ARB regulations can be sold in the
State of California.
Refer to the specific EPA / ARB installation (page
40) and maintenance ( page 40) i n the Peri odic
Maintenance Sc hedule section of this manual.
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 9
Emission Control Labels
Since emission contr ol r egulations are being issued
on a global basis, it is necessary to identify which
regulati ons a particular engine complies with. We
have listed sev er al diff erent types of labels you
might find on your engine.
EPA / ARB Labels
(EPA) Greater than or Equal to 50 HP SAE (37kW)
(EPA and ARB)
The 97/68/EC Directive Certified
Engines
The engines described i n this manual have been
certifi ed by the 97/68/ E C Dir ec tive.
To identif y the engines that meet this certification,
the 97/68/EC emission control label is affixed on
the engines
(97/68/EC)
Engine Family
The EPA / ARB labels and the 97/68/EC label all
have an Engine Family field. The following is an
explanati on of t he Engi ne Family desi gnation:
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 10
Function of Major Engine Components
Components Functions
Air Cleaner
The air cleaner prevents airborne contaminants from enteri ng the
engine. Since t he air cleaner is application specific, it must be carefully
selected by an applic ation engineer. It is not part of the basic engine
package as shipped from the Yanmar factory. Periodic replacement of
the air cleaner filt er elem ent is necessary. See the Periodic Maintenance
Schedule on page 39 for the replac em ent f r equenc y.
Dipstick (Engine Oil )
The alternator is driven by a V-belt which is powered by the crankshaft
V-pulley. The alternator supplies electrici ty to the engine systems and
charges the battery while the engine is running.
Dipstick (Engine Oil )
The engine oil dipstic k is used to determ ine the amount of engine oil in
the crankcase.
Electric Fuel Pump
(If Equipped)
The electric f uel pum p makes sure there is a constant supply of diesel
fuel to the fuel injec tion pump. The electric fuel pump is electro-magnetic
and runs on 12 VDC. An electic fuel pump may be installed as an option
or as standard equipment. Standard equipment may vary based on
engine model and specification. If an electic fuel pum p is install ed, turn
the key switch to the ON position for 10 to 15 seconds to prime the fuel
system.
Engine Oil Filter
The engine oil filt er removes contaminants and sediments from the
engine oil. Periodic replacement of the engine oil filter is necessary. See
the Periodic Mai ntenance S c hedule on page 39 for the replacement
frequency.
Engine Oil Cooler
(If Equipped)
The engine oil cool er hel ps to keep the engine oil cool. Engine coolant
from the cooling system is circulated through an adapt er at the base of
the engine oil filt er assembly and then returned to the coolant pump
inlet.
Fuel Filter
The fuel filter remov es contaminants and sediments from the diesel fuel.
Periodic replacement of the fuel filter is necessary. See the Periodic
Maintenance Sc hedule on page 39 for the replacement frequency.
Please note that the word “di esel” is implied throughout this
manual when the word “fuel” is used.
Fuel Filter/ Water Separator
The fuel filter / water separator r emoves contaminants, sediments and
water from the diesel fuel going to the fuel filter. This is a required
component of the fuel system. This is standard equipment with every
engine. The separator is installed between the fuel tank and the electric
fuel pump. Periodically drain the water from the fuel filter / water
separator.
Fuel Priming Lever
(If Equipped)
If the unit has a mechanic al fuel pump, a fuel priming lever on the
mechanical fuel pum p primes the fuel system. The fuel sytem needs to
be primed before you start the engine for the first time, if you run out of
fuel, or if fuel system servic e is performed. To prime the fuel system,
operate the fuel primi ng lever until the cup in the fuel filter i s full of f uel.
Fuel Tank
The fuel tank is a reservoir that holds diesel fuel. When the fuel leav es
the fuel tank it goes to the fuel filter / water separator. Next the fuel is
pumped to the fuel filter by the electric fuel pump. Then the fuel goes to
the fuel injection pump. Since the fuel is used to keep the fuel injection
pump cool and lubricat ed, more fuel than necessary enters the i njec tion
pump. When the injection pump pressure reaches a preset v alue, a relief
valve allows the excess fuel to be returned back to the fuel tank. The fuel
tank is a required engine component.
Side and Top Filler Port
(Engine Oil)
You can fill the crankcase with engine oil f r om either the side or the top
filler port dependi ng upon whic h one is most convenient.
Starter Motor
The starter motor is powered by the bat tery. When you turn the key
switch in the operat or’s console to the START posi tion, the starter motor
engages with the ri ng gear installed on the flywheel and starts the
flywheel in motion.
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 11
Function of Cooling System Components
Components Functions
Cooling System
The TNV engine is liquid-cooled by means of a cooling system. The
cooling system consi sts of a r adiator, radiator cap, engine cooling
fan, engine coolant pump,thermostat, and reserve tank. Note that
all cooling system compo nents are required for proper engine
operation. Since some of the components are application
specific, th ey must be careful ly selected by an application
engineer. The application specific items are not part of the
basic engine package as shipped fro m th e Yanmar factory.
Engine Cooling F an
The engine cooli ng fan is driven by a V-belt which is powered by the
crankshaft V-pulley. The purpose of the engine cooling fan is to
circulate air through the radiator.
Engine Coolant Pump
The engine coolant pum p ci r c ulates the engine coolant through the
cylinder bl ock and t he cylinder head and returns the engine coolant
to the radiator.
Radiator
The radiator acts as a heat exchanger. As the engine coolant
circulates thr ough the cylinder block it absorbs heat. The heat in the
engine coolant is di ssipated i n the radiator. As the engine cool ing fan
circulates ai r thr ough the radiator, the heat is transferred to the air.
Radiator Cap
The radiator cap controls the cooling system pressure. The cooling
system is pressurized t o r aise the boiling point of the engine c oolant.
As the engine coolant t em per ature rises, the system pressure and
the coolant vol um e increases. When the pressure reaches a preset
value, the rel ease valve in the radiator cap opens and the excess
engine coolant flows into the reserve tank. As the engine coolant
temperature is reduced, the system pressure and volume is reduced
and the vacuum valve in the radiator cap opens allowing the engine
coolant to flow from the reserve tank back into the radiator.
Reserve Tank
The reserve tank contains the overflow of engine coolant from the
radiator. If you need to add engine coolant to the system , add it to
the reserve tank; not the radiator.
Thermostat
A thermostat is placed in the cooling system to prevent the engi ne
coolant from cir c ulating into the radiator until the engine coolant
temperature reac hes a preset temperature. When t he engine is cold,
no engine coolant flows through the radiator. Once the engine
reaches its operating tem perature, the therm ostat opens and allows
the engine cool ant t o flow through t he r adiator. By letting the engine
warm up as quickly as possible, the thermostat reduces engine
wear, deposits and emissions.
Section 1. Componen t Iden tif ication 12
Diesel Fuel
Diesel Fuel Specifications
Diesel fuel should com ply with the following
specifications. The table lists several worldwide
specifications for diesel fuels.
.
Diesel Fuel
Specification
Location
No. 2-D, No. 1-D,
ASTM D975-94
USA
EN590:96
European
Union
ISO 8217 DMX International
BS 2869-A1 or A2
United
Kingdom
JIS K2204 Grade No.
2
Japan
KSM-2610 Korea
GB252 China
Additi ona l Techn ic a l Fue l Re q uir ements
• The fuel cetane number should be equal to 45 or higher.
• The sulfur content must not exceed 0.5% by volume. Less
than 0.05% is preferred.
• Bio-Diesel fuels. See Bio-Diesel Fuels on page 4-9.
• NEVER mix kerosene, used engine oil, or residual fuel s with
the diesel fuel.
• The water and sediment in the fuel should not exceed 0.05%
by volume.
• Keep the fuel tank and fuel-handling equipment clean at all
times.
• Poor quality fuel can reduce engine performance and / or
cause engine damage.
• Fuel additives are not recommended. Some fuel additives may
cause poor engine performance. Consult your Yanmar
representative for more information.
• The ash content must not exceed 0.01% by volume.
• The carbon residue content must not exceed 0.35% by volume.
Less than 0.1% is preferred.
• The total aromatics content should not exceed 35% by volume.
Less than 30% is preferred.
• The PAH (polycyclic aromatic hydrocarbons) content should
be below 10% by volume.
• The metal content of Na, Mg, Si, and Al should be equal to or
lower than 1 mass ppm. (Test analysis method JPI-5S-44-95)
• Lubricity: The wear mark of WS1.4 should be Max. 0.018 in
(460 μm) at HFRR test.
Bio-Diesel Fuel s
In Europe and in the United States, as well as some
other countries, non-mineral oil based fuel
resources such as RME (Rapeseed Methyl Ester)
and SOME (Soybean Methyl Ester) , collectively
known as FAME (Fatty Aci d M ethyl E sters), are
being used as extenders f or mineral oil derived
diesel fuels.
Yanmar approves the use of bio-diesel fuels that do
not exceed a blend of 5% (by volume) of FAME with
95% (by volume) of approv ed mi ner al oil der ived
diesel fuel. S uc h bio- diesel fuels are known in the
marketplac e as B5 diesel fuels.
These B5 diesel fuel s must meet certain
requirements.
1. The bio-fuels must meet the minimum
specifications for the country in which they
areused.
• In Europe, bio-diesel fuels must comply with the European
Standard EN14214.
• In the United States, bio-diesel fuels must comply with the
American Standard ASTM D-6751.
2. Bio-fuel s should be purc hased onl y from
recognized and author ized diesel fuel suppliers.
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 13
Precautions and concerns regarding the use of
bio-fuels:
1. Free methanol in FAME may result in corrosion of
aluminum and zinc FIE components.
2. Free water in FAME may result in plugging of fuel
filters and increased bact er ial growth.
3. High viscosity at low temperatures may result in
fuel deliv ery problems, injection pump seiz ures,
and poor injection nozzle spray atomizati on.
4. FAME may have adverse effects on some
elastomers (seal materials) and may result i n fuel
leakage and diluti on of the engine lubricating oil.
5. Even bio-diesel fuels that comply with a suitable
standard as deliv ered, wil l r equire additional care
and attenti on to maintain the quality of the fuel in
the equipment or other fuel tanks. It is important
to maintain a supply of clean, fresh fuel. Regular
flushing of the f uel system, and / or fuel storage
containers, may be necessary.
6. The use of bio-diesel fuels that do not comply with
the standards as agreed to by the diesel engine
manufacturers and the diesel fuel injection
equipment manuf actur er s, or biodiesel fuels that
have degraded as per the precautions and
concerns above, may affect the warranty
coverage of your engine.
Filling The Fuel Tan k
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
Only fill the fuel tank with diesel fuel. Filling the
fuel tank with gasoline may result in a fire and
will damage the engine.
NEVER refuel with the engine running.
Wipe up all spills immediat ely.
Keep sparks, open flames or any other form of
ignition (mat ch, cig arette, static electric source)
well away when refueling.
NEVER overfill the fuel tank.
Fill the fuel tank. Store any containers
containing fuel in a well-ventilated area, away
from any combustibles or sources of ignition.
Failure to comply will result in death or serious
injury.
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
Be sure to place the diesel fuel container on the
ground when transferring the diesel fuel from
the pump to the container. Hold the hose nozzle
firmly against the side of the container while
filling it. This prevents static electricity buildup
which could cause sp arks and ignite f uel vapors.
NEVER place diesel fuel or other flammable
material such as oil, hay or dri ed grass close to
the engine during engine operation or shortly
after shutdown.
Failure to comply will result in death or serious
injury.
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 14
DANGER
FIRE AND EXPLOSION HAZARD
!
Diesel fuel is flammable and explosive under
certain conditions.
Before you operate the engine, check for fuel
leaks. Replace ru bberized fuel hoses every two
years or every 2000 hours of engine operation,
whichever comes first, even if the engine has
been out of service. Rubberized fuel lines tend
to dry out and beco me brittle after two years or
2000 hours of engine operation, whichever
comes first.
Failure to comply will result in death or serious
injury.
CAUTION
Only use diesel fuels recommended by Yanmar
for the best engine performance, to prevent
engine
damage and to comply with EPA / ARB warranty
requirements.
Only use clean diesel fuel.
NEVER remove the primary strainer (if equipped)
from the fuel tank filler port. If removed, dirt and
debris could get into th e fuel system causing it
to clog.
Note that a typical f uel tank is shown. The fuel tank
on your equipment m ay be different.
1. Clean the area around the fuel cap (Figure 4-3,
(1)).
2. Remove the fuel cap (Figu re 4- 3, ( 1) ) from the
fuel tank (Figure 4-3, (2)).
3. Observe the fuel lev el si ght gauge (Figure 4-3,
(3)) and stop fueling when the gauge shows the
fuel tank is f ull. NEVER overfill the f uel tank.
4. Replace the fuel cap (Figure 4-3, ( 1) ) and hand
tighten. Ov er-ti ghtening the fuel cap will damage
it.
Figure 4-3
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 15
Priming the Fuel System
The fuel system needs to be prim ed under c ertain
conditions.
• Before starti ng the engine for the first time.
• After running out of f uel and fuel has been added
to the fuel tan k .
• After fuel system maintenance such as changing
the fuel filter and draining the fuel filter / water
separator, or repl aci ng a fuel system component.
To prime the fuel system on engines equipped with
an electric fuel pump:
1. Place an approv ed container under the air bleed
port.
2. Loosen the air bleed port 2 or 3 turns.
3. Turn the key to the ON position for 10 to 15
seconds or until the fuel coming out of the air
bleed port is free of bubbl es.
4. Tighten the air bleed port.
5. Wipe up any spills and properly dispose of fuel.
6. NEVER use the starter motor to crank the engine
in order to prime the fuel system. This may cause
the starter motor to over heat and damage the
coils, pinion and/ or ri ng gear.
To prime the fuel system on engines not equipped
with an electri c fuel system :
1. Place an approv ed container under the air bleed
port.
2. Loosen the air bleed port (F ig ure4-4, (1)) 2 or 3
turns.
3. Operate the fuel priming pump (Figure4-4, (2))
until the fuel coming out of the air bleed port is
free of bubbles.
4. Tighten the air bleed port.
5. Wipe up any spills and properly dispose of fuel.
6. NEVER use the starter motor to crank the engine
in order to prime the fuel system. This may cause
the starter motor to over heat and damage the
coils, pinion and/ or ri ng gear.
Figure 4-4
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 16
Engine Oil
CAUTION
Only use the engine oil specified.
Other engine oils may affect warranty coverage,
cause internal engi ne components to seize and /
or shorten engine life.
Prevent dirt and debris from contaminating the
engine oil. Carefully clean the oil cap / dipstick
and the surrounding area before you remove the
cap.
NEVER mix different types of engine oil. This
may adversely affect the lubricating properties
of the engine oil.
NEVER overfill. Overfilling may result in white
exhaust smoke, engine overspeed or internal
damage.
Engine Oil Specifications
Use an engine oil that meets or exceeds the
following guidelines and classific ations:
Service Categories
• API Service Categories CD or higher
• ACEA Service Categor ies E-3, E-4, and E-5
• JASO Service Category DH- 1
Definitions
• API Classification (American Petroleum Institute)
• ACEA Classifi c ation (Association des
Constructeurs Européens d'Automobilies)
• JASO (Japanese Automobile Standards
Organization)
NOTE:
• Be sure the engine oil, engi ne oil stor age
containers, and engine oil filling equipment aref r ee
of sediment and water.
• Change the engine oil after the first 50 hours of
peration and then ev er y 500 hours ther eafter.
• Select the oil vi scosity based on the ambient
temperature where the engine is being operated.
See the SAE Service Grade Viscosity Char t
(Figure 4-4a)
• Yanmar does not r ec ommend the use of engine oil
“additives.”
Additional Technical Engine Oil
Requirements:
The engine oil must be changed when the Total
Base Number (TBN) has been reduced t o 1.0
mgKOH /g test method; JIS K-201-5.2-2 (HCI),
ASTM D4739 (HCI).
Engine Oil Viscosity
Select the appropriate engine oil viscosity based on
the ambient temperature and use the SAE Service
Grade Viscosity Chart in Figure 4-4a.
Figure 4-4a
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 17
Checking Engine Oil
1. Make sure the engine is level.
2. Remove the dipstick (Figure 4-5, (1)) and wipe it
with clean clot h.
3. Fully reinsert the dipstick.
4. Remove the dipstick. The oil level should be
between the upper (Figu re 4- 5, (2)) and lower
(Figure 4-5, (3) ) li nes on the dipstick.
5. Fully reinsert the dipstick.
Figure 4-5
Adding Engine Oil
1. Make sure the engine is level.
2. Remove the oil cap (Figure 4-5, (4)).
3. Add the indicated amount of engine oil at the top
or the side engine oil fill er por t (Figure 4-5, (5)).
4. Wait three minutes and check the oil level.
5. Add more oil if necessary.
6. Reinstall the oil cap (Figu re 4- 5, (4)) and hand-
tighten. Ov er-ti ghtening may damage the cap.
Engine Oil Capacity (Typical)
NOTE: These are the engine oil capacities
associated with a “deep standard” oil pan. The oil
capacity will vary dependant upon which optional oil
pan is used. Refer to the operation m anual provided
by the driven machine manufacturer for the actual
engine oil capacity of your m achi ne.
The following are the engine oil capacities for
various Yanmar engines.
Engine Model
Dipstick Upper
Limit / Lower Limit
4TNV98
11.1 / 6.3 qt
(10.5 / 6.0 L)
4TNE98
9.7 / 7.6 qt
(9.2 / 7.2 L)
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 18
Engine Coolant
DANGER
SCALD HAZARD!
NEVER remove the radiator cap if the engine is
hot. Steam and hot engine coolant will spurt out
and seriously burn you. Allow the engine to cool
down before you attempt to remove the radiator
cap.
Tighten the radiator cap securely after you
check the radiator. Steam can spurt out during
engine operation if the cap is loose.
ALWAYS check the level of the engine coolant
by observing the reserve tank.
Failure to comply will result in death or serious
injury.
WARNING
BURN HAZARD!
Wait until the engine cools before you drain
the engine coolant. Hot engine coolant may
splash and burn you.
Failure to comply could result in death or
serious injury.
CAUTION
COOLANT HAZARD!
Wear eye protection and rubber gloves when
you handle long life or extended life engine
coolant. If contact with the eyes or skin should
occur, flush eyes and wash immediately with
clean water.
Failure to comply may result in minor or
moderate injury.
CAUTION
Only use the engine coolant specified. Other
engine coolants may affect warranty coverage,
cause an internal build up of rust and scale and /
or shorten engine life.
Prevent dirt and debris from contaminating the
engine coolant. Carefully clean the radiator cap
and the surrounding area before you remove the
cap.
NEVER mix different types of engine coolants.
This may adversely affect the properties of the
engine coolant.
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 19
Engine Coolant Specifications
Use a Long Life Coolant (LLC) or an Ext ended Life
Coolant (ELC) that meets or exceeds the following
guidelines and specifications:
Additi ona l Techn ic a l C oo la nt
Specifications:
• ASTM D6210, D4985 (US)
• JIS K-2234 (Japan)
• SAE J814C, J1941, J1034 or J2036 (Int ernational)
Alternative Engi ne Coolant
If an Extended or Long Life Coolant is not available,
alternativ ely, you may use an ethylene glycol or
propylene gly c ol based conventional coolant
(green).
Notes:
• ALWAYS use a mix of coolant and water. NEVER use water
only.
• Mix the coolant and water per the mixi ng instructions on the
coolant container.
• Water quality is important to coolant performance. Yanmar
recommends that soft, distilled, or demineralized water be
used to mix with coolants.
• NEVER mix extended or long life coolants and conventional
(green) coolants.
• NEVER mix different types and / or colors of extended life
coolants.
• Replace the coolant every 1000 engine hours or once a year.
Filling Radiator with Engine Coolant
Fill the radiator and r eserve tank as follows. This
procedure is for filling the radiator for the first time
or refilling it after it i s flushed. Note that a typical
radiator is illustrated (Figure 4-6).
Figure 4-6
1. Check to be sure the radiator drain plug
isinstalled and ti ghtened or the drain cock(Figure
4-6, (1)) is closed. Also make sure thecool ant
drain plug (Figure 4- 7, (1)) in thecylinder block is
closed or the oil cool ant hoses(Fi gure 4-8, (1))
are installed at the oil c ooler.
Figure 4-7
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 20
Figure 4-8
2. Remove the radiat or cap (Figure 4-6, (2)) by
turning it counter - cl oc k wi se about 1/3 of a turn.
3. Pour the engine coolant sl owly into the radiator
until it is even with the lip of the engine coolant
filler port. M ak e sure that air bubbles do not
develop as you fill the radiator.
4. Reinstall the radiator cap (Figure 4-6, (2)).Align
the tabs on the back side of the radiator c ap with
the notches on the engine c oolant filler port.
Press down and turn the cap cloc k wise about 1/3
of a turn.
5. Remove the cap on the reserve tank (Figure 4-6,
(3)), and fill it to the LOW (COLD) mark (Figure
4-6, (4)) with engine c oolant. Reinstall the cap.
6. Check the hose (Figure 4-6, ( 5) ) that connects
the reserve tank (Figure 4-6, (3)) to the radiator.
Be sure it is securely connec ted and there are no
cracks or damage. If t he hose is dam aged, the
engine coolant will leak out instead of going into
the reserve tank.
7. Run the engine until it is at oper ating temperature.
Check the level of engine coolant in the reserve
tank. When the engine is running and the engine
coolant is at normal temperature, the coolant
level in the tank should be at the FULL (HOT)
mark (Figure 4-6, (6)). If the engi ne c oolant is not
at the FULL (HOT) mark (Figure 4-6, (6)), add
additional engine coolant to the reserve tank to
bring the level t o the FULL (HOT) mark.
Engine Coolant Capacity (Typical)
NOTE: The capacities listed are for the engineonly
without a radiator. Ref er to t heoper ation manual
provided by the drivenmachine manufacturer for the
actualengi ne c oolant capacity on yourmachine.
The following are the engine coolant capacities for
various Yanmar engines.
Engine Model
Engine Coolant
Capacity
4TNV98 4.4 qt (4.2 L)
4TNE98 4.4 qt (4.2 L)
Specifications
Description of Model Number
When ordering parts or making an inqui r y about t he
engine you are working on, be sure t o incl ude the
complete model and serial numbers as shown on
the engine namepl ate. See Location of Labels on
page 8.
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 21
Engine General Specifications
Type
Vertical In-line, Water Cooled,
4-Cycle Diesel Engine
4TNV98 Direct Injection
Combustion
System
4TNE98 Indirect Injection
Starting System Electric Starting
Cooling System Radiator
Lubricating
System
Forced Lubric ation with
Trochoid Pump
PTO Position Flywheel End
Direction of
Rotation
Counterclock wise Viewed f r om
the Flywheel End
NOTE: The information described in Principal
Engine Specifications is for a “standard” engine. To
obtain the information for the engine installed in your
driven machine, please refer to the manual provided
by the driven machine manufacturer. Engine rating
conditions are as follows (SAE J1349, ISO 3046/1):
• Atmospheric Condi tion: Room temperature 77°F
(25°C), Atmospheri c pr essure 29.53 in Hg (100
kPa, 750 mm Hg), Relativ e humi dity 30%
• Fuel Temperature at F uel Injector Pump Inlet:
104°F (40°C)
• With Cooling Fan, Air Cl eaner , Muff ler: Yanmar
Standard
• After Engine Break -In P eri od; Output Allowable
Deviation: ± 3%
• 1 PS = 0.7355 kW
• 1 hp SAE (Society of Automotive Engineers) =
0.7457 kW
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 22
Principal Engine Specifications
4TNV98 EPA Tier 2
Engine Model 4TNV98
Version VM (SDF)
Type Vertical In-line Diesel Engine
Combustion System Direct Injecti on
Aspiration Natural
No. of Cylinders 4
Bore × Stroke 3.858 x 4.331 in. (98 x 110 mm)
Displacement 202.502 cu in. (3.319 L)
RPM 2200
hp SAE 61.2
kW 45.6
Max. Rated Output (Net )
PS 62.0
High Idling RPM 2400±25
Engine Weight (Dry)
with Flywheel Housing
518.2 lb (235 kg)
PTO Position Flywheel End (Opti on)
Direction of Rotation Counterclock wise Viewed f r om Fl y wheel E nd
Cooling System Liquid-Cooled with Radiator
Lubricating Sy stem Forced Lubric ation with Trochoid Pump
Normal Oil Pressure at
Rated Engine Speed
42 - 57 psi (0.29 - 0.39 MPa, 2.96 - 3.98 kgf/cm²)
Normal Oil Pressure at
Low Idle Speed
8.5 psi (0.06 MPa, 0.6 kgf/cm²)or greater
Electric Starting - Starter Motor: DC12V, 3.1 hp (2.3 kW)**
Alternat or: DC12V, 40A**
Starting System
Recommended Batter y Capacity : 12V, 64 Amp-Hour ( 5h rating)**
Dimensions (L × W × H)*
28.31 x 19.61 x 29.21 in.
(719 x 498 x 742 mm)
Engine Oil Pan 11.1 / 6.3 qt (10.5 / 6.0 L) (Dipstick Upper Limit / Lower Limi t)
Engine Coolant Capacit y 1.1 gal (4.2 L) Engine Onl y
Standard Cooling Fan 16.14 in. (410 mm) O.D., 6 Blade P usher-Type**
* Engine specific ations without radiat or
** May vary depending on application.
*** Engine oil capacity for a “Deep Standard” oil pan. Refer to the operat ion manual provided by the driven
machine manufactur er for the actual engine oil capacity of y our machine.
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 23
4TNE98 EPA Tier 3
Engine Model 4TNE98 EPA Tier 3
Version VM (BQDF(C))
Type Vertical Inline Diesel Engine
Combustion System Indirect Injec tion, No Turbocharger
Aspiration Natural
No. of Cylinders 4
Bore × Stroke 3.86 x 4.33 in. (98 x 110 mm)
Displacement 202. 5 c u in. (3.319 L)
RPM
(min
-1
)
2300
hp SAE 58.6
kW 43.7
**Max. Rated Output
(Gross)
PS 59.4
High Idling Speed
(Bare Engine)
2625±25
Low Idling Speed
(Bare Engine)
850±25 rpm
Engine Weight (Dry) * 496 lb ( 235 k g)
PTO Position Flywheel Side
Direction of Rotation Counterclock wise Viewed From Flywheel Side
Cooling System Liquid-Cooled With Radiator
Lubricating Sy stem
Forced Lubric ation With Trochoid Pump
At normal operating speeds, oi l pressure is: 42-57 psi
(0.29 - 0.39 MPa; 3.0 – 4.0 kgf/cm ²)
At idle, oil pressure is: No l ess than 18. 5 psi (0. 13 M pa; 1. 3k gf/cm²)
Electric Starting - Starter Motor: DC12V, 3.1 hp (2.3 kW)
Alternat or: DC12V, 80A
Starting System
Recommended Batter y Capacity : 12V, 622 CCA
(Cold Cranki ng Amps)
Dimensions (L × W × H)*
28.0 x 20.3 x 29.8 in.
(710 x 516 x 758 mm)
Engine Oil Pan Capacity
9.7 / 7.6 qt (9.2 / 7.2 L)
(Dipstick Upper Limit / Lower Lim it)
Engine Coolant Capacit y 1.11 gal ( 4.2 L) Engi ne Only
* Engine Specifications Without Radiator, Muffler, and Air Cleaner.
** The Intake and Exhaust conditi on of Max. Rated output are
Air Intake Restriction : 250mm A q
Exhaust Gas Restri ction : 1000mmAq
***The detail specific ations are refer to the Specification document which is agreed between both engineeri ng.
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 24
Engine Service Standards
Inspection Item Standard Limit
Reference
page
Intake / Exhaust Valve Clearance
0.006 - 0.010 in.
(0.15 - 0.25 mm)
-
See Measuring
and Adjusting
Valve Clearance
on page 104
4TNV98 See Checking and Adjusting Fuel Injection Timing on page 157.
Fuel Injection
Timing
4TNE98 8.5°±1° ATDC -
With Plunger Lifted
0.039 in (1mm)
4TNV98 See Test and Adjustment Specifications on page 144.
Fuel Injection
Pressure
4TNE98
1711-1842 psi
(11.8 - 12.7 Mpa;
120 - 130 kgf / cm²
- -
4TNV98
483 - 513 psi
(3.33 - 3.53 MPa;
34 - 36 kgf / cm²)
384 - 414 psi
(2.65 - 2.85 MPa;
27 - 29 kgf / cm²)
See
Troubleshooting
By Measuring
Compression
Pressure on
page 236
Compression
Pressure at 250
rpm 250 min¯¹)
4TNE98
425 - 428 psi
(2.93 – 2.95 MPa;
29 - 31 kgf / cm²)
341 psi
(2.35 MPa;
24 kgf / cm²)
-
Deviation Bet ween Cyli nder s
29 - 43 psi
(0.2 - 0.3 MPa;
2 - 3 kgf/cm²)
- -
Oil Pressure Switch Operating Pressure
5.8 - 8.8 psi
(0.04 - 0.06 MPa;
0.4 - 0.6 kgf / cm²)
- -
Max.(when cold)
86 psi
(0.59 MPa;
6.0 kgf / cm²)
- -
At rated Output
42 - 57 psi
(0.29 - 0.39 MPa;
2.96 - 3.98 kgf / cm²)
- -
Lubricating Oil
Pressure
When idling
8.5 psi
(0.06 MPa;
0.6 kgf / cm²)
or greater
- -
Valve Opening
Temperature
Full Opening Lift
Temperature
Option
157°F - 163°F
(70°C - 73°C)
0.32 in (8 mm) or
Above
185°F (85°C)
Thermostat
Standard
176°F - 183°F
(80°C - 84°C)
0.39 in (10 mm)
or
above
203°F (95°C)
See Thermostat
on page 207
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 25
Tightening Torques for Standard
Bolts and Nuts
Use the correct amount of torque when you tighten
the fasteners on the m ac hine. Applying excessiv e
torque may damage the fastener or c omponent and
not enough torque may cause a l eak or component
failure.
CAUTION
The tightening torque in the Standard Torque
Chart (see General Service Information section)
should be applied only to the bolts with a “7”
head. (JIS strength classification: 7T)
Apply 60% torque to bolts
that are not list ed.
Apply 80% torque when
tightened to aluminum alloy.
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 26
Item
Nominal Thread
Diameter x Pitch
Tightening Torque Remarks
M6 x 1.0 mm
7 - 9 ft·lb
(87 -104 in·lb,
9.8 -11.8 N·m,
1.0 -1.2 kgf·m)
M8 x 1.25 mm
17 - 21 ft·lb
(200 - 251 in.·lb,
22.6 - 28.4 N·m,
2.3 - 2.9 kgf·m)
M10 x 1.5 mm
33 - 40 ft·lb
(44.1 - 53.9 N·m,
4.5 - 5.5 kgf·m)
M12 x 1.75 mm
58 - 72 ft·lb
(78.4 - 98.0 N·m,
8.0 - 10 kgf·m)
M14 x 1.5 mm
94 - 108 ft·lb
(127.5 - 147.1 N·m,
13 - 15 kgf·m)
Hexagon Bolt (7T) and
Nut
M16 x 1.5 mm
159 - 174 ft·lb
(215.7- 235.4 N·m,
22 – 24 kgf·m)
Use 80% of the
value at left when
the tighteni ng part
is aluminum.
Use 60% of the
value at left for 4T
bolts and lock nuts.
1/8 mm
7 ft·lb (87 in.·lb,
9.8 N·m, 1.0 kgf·m)
1/4 mm
14 ft·lb (173 in.·lb,
19.6 N·m, 2.0 kgf·m)
3/8 mm
22 ft·lb
(29.4 N·m, 3.0 kgf·m)
PT PLug
1/2 mm
43 ft·lb
(58.8 N·m, 6.0 kgf·m)
Item
Nominal Thread
Diameter x Pitch
Tightening Torque Remarks
M8
9 - 12 ft·lb
(112 - 148 in.·lb,
12.7 - 16.7 N·m,
1.3 - 1.7 kgf·m)
M10
14 - 19 ft·lb
(173 - 225 in.·lb,
19.6 - 18.734 N·m,
2.0 - 3.5 kgf·m)
M12
18 - 25 ft·lb
(24.5 - 34.3 N·m,
2.5 - 3.5 kgf·m)
M14
29 - 36 ft·lb
(39.2 - 49. 0 N·m,
4.0 5.0 kgf·m)
Pipe Joint Bolt
M16
36 - 43 ft·lb
(49.0 - 58.8 N·m,
5.0 - 6.0 kgf·m)
.
NOTE: Torque values shown in t his manual are for clean, non-lubricated fasteners unless otherwise specified.
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 27
Abbre viations and S ym bo ls
Abbreviations.
A ampere
AC alternating current
ACEA Association des Constructeurs
Européens d’Automobilies
Ah ampere-hour
API Americ an Pet r oleum Ins t itu te
ARB Air Resources Board
ATDC aft er top dead center
BDC bottom dead center
BTDC before top dead center
°C degree Celsius
CARB California Air Resources Board
CCA cold cranking amp
cfm cubic feet per minute
cm centimeter
cm³ cubic centimeter
cm³/min cubic centimeter per minute
cu in. cubic inch
D diameter
DC direct current
DI direc t injectio n
DVA dir ect volt adapter
EPA Environmental P r otec t ion A gency
ESG el ectroni c speed governo r
°F degree Fahrenheit
fl oz fl uid ounce (U.S.)
fl oz/min fluid ounce (U.S.) per minute
ft foot
ft-lb f oot pound
ft-lbf/min foot pound force per minute
g gram
gal gallon (U.S.)
gal/hr gallon (U.S.) per hour
gal/min gallon (U.S.) per minute
GL gear lubricant
hp horsepower (U.S.)
hr hour
I.D. in side d i ameter
ID identification
IDI indirect injection
in. inch
in.Aq inches Aqueous (water)
in.Hg inches M ercury
in.-lb inch pound
j joule
JASO
Japanese Automobile Standards
Organization
k kelvin
kg kilogram
kgf/cm² kilogram force per square centim eter
kgf/m kilogram force per meter
km kilometers
kPa kilopascal
kW kilowatt
L liter
L/hr liter per hour
lb pound
lbf pound force
m meter
mL milliliter
mm millimeter
mmAq millimeter Aqueous (water)
MPa megapascal
mV millivolt
N newton
N·m newton meter
No. number
O.D. outside diameter
oz ounce
Pa pascal
PS horsepower (metric)
psi pound per square inch
qt quart (U.S.)
R radius
rpm revolutions per minute
SAE Society of Automot ive E ngin eers
sec. second
t short ton 2000 lb
TBN total base number
TDC top dead center
V volt
VAC volt alternating current
VDC volt direct current
W watt
Symbols
°
degree
+
plus
-
minus
±
plus or minus
Ω
ohm
μ
micro
%
percent
4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 28
Unit Conversions
Unit Prefixes
Prefix Symbol Power
mega M x 1,000,000
kilo k x 1,000
centi c x 0.01
milli m x 0.001
micro μ x 0.000001
Units of Length
Mile x 1.6090 = km
ft x 0.3050 = m
in. x 2.5400 = cm
in. x 25.4000 = mm
km x 0.6210 = mile
m x 3.2810 = ft
cm x 0.3940 = in.
mm x 0.0394 = in.
Units of Volume
gal (U.S.) x 3.78540 = L
qt (U.S.) x 0.94635 = L
cu in. x 0.01639 = L
cu in. x 16.38700 = mL
fl oz(U.S.) x 0.02957 = L
fl oz(U.S.) x 29.57000 = mL
cm³ x 1.00000 = mL
cm³ x 0.03382 =floz(U.S.)
Units of Mass
lb x 0.45360 = kg
oz x 28.35000 = g
kg x 2.20500 = lb
g x 0.03527 = oz
Units of Force
lbf x 4.4480 = N
lbf x 0.4536 = kgf
N x 0.2248 = lbf
N x 0.1020 = kgf
kgf x 2.2050 = lbf
kgf x 9.8070 = N
Units of Torque
ft-lb x 1.3558 = N·m
ft-lb x 0.1383 = kgf/m
in.-lb x 0.1130 = N·m
in.-lb x 0.0115 = kgf/m
kgf/m x 7.2330 = ft-lb
kgf/m x 86.8000 = in.-lb
kgf/m x 9.8070 = N·m
N·m x 0.7376 = ft-lb
N·m x 8.8510 = in.-lb
N·m x 0.1020 = kgf/m
Units of Pressure
psi x 0.0689 = bar
psi x 6.8950 = kPa
psi x 0.0703 = kg/cm²
bar x 14.5030 = psi
bar x 100.0000 = kPa
bar x 29.5300 =inHg(60°F)
kPa x 0.1450 = psi
kPa x 0.0100 = bar
kPa x 0.0102 = kg/cm²
kg/cm² x 98.0700 = psi
kg/cm² x 0.9807 = bar
kg/cm² x 14.2200 = kPa
in.Hg (60°) x 0.0333 = bar
in.Hg (60°) x 3.3770 = kPa
in.Hg (60°) x 0.0344 = kg/cm²
mmAq x 0.0394 = in.Aq
Units of Power
hp
(metric
or PS)
x 0.9863201 = hp SAE
hp
(metric
or PS)
x 0.7354988 = kW
hp SAE x 1.0138697 =hp(metric
or PS)
hp SAE x 0.7456999 = kW
kW x 1.3596216 =hp(metric
or PS)
kW x 1.3410221 = hp
SAE
Units of Temperature
°F = (1.8 x °C) + 32
°C = 0.556 x (°F - 32)
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 29
Section 2. PERIODIC MAINTENANCE
Before You Begin Servicing
DANGER
EXPLOSION HAZARD!
NEVER check the remaining battery charge by
shorting out the terminals. This will result in a
spark and may cause an explosion or fire. Use a
hydrometer to check the remaining battery
charge.
If the electrolyte is frozen, slowly warm the
battery before you recharge it.
Failure to compl y will result in death or serious
injury.
DANGER
FIRE AND EXPLOSION HAZARD!
Only use the key switch to start the engine.
NEVER jump-start the engine. Sparks caused by
shorting the battery to the starter terminals may
cause a fire or explosio n.
Failure to compl y will result in death or serious
injury.
DANGER
SCALD HAZARD!
NEVER remove the radiator cap if the engine is
hot. Steam and hot engine coolant will spurt out
and seriously burn you. Allow the engine to
cool down before you attempt to remove the
radiator cap.
Tighten the radiator cap securely after you
check the radiator. Steam can spurt out during
engine operation if the cap is loose.
ALWAYS check the level of the engine coolant
by observing the reserve tank.
Failure to compl y will result in death or serious
injury.
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
Only fill the fuel tank with diesel fu el. Filling the
fuel tank with gasoline may resu lt in a fire and
will damage the engine.
NEVER refuel with the engine running.
Wipe up all spills immediat ely.
Keep sparks, op en flames or any other form o f
ignition (mat ch, cigarette, stati c electric source)
well away when refueling.
NEVER overfill the fuel tank.
Fill the fuel tank. Store any containers
containing fuel in a well-ventilated area, away
from any combustibles or sources of ignition.
Failure to compl y will result in death or serious
injury.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 30
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
Before you operate the engine, check for fuel
leaks. Replace rubberi zed fuel hoses every two
years or every 2000 hours of engine operation,
whichever comes first, even if the engine has
been out of service. Rubberi zed fuel lines tend
to dry out and become brittle after two years or
2000 hours of engine operation, whichever
comes first.
Failure to compl y will result in death or serious
injury.
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
NEVER remove the fuel cap with the engine
running.
Failure to compl y will result in death or serious
injury.
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
Be sure to place the diesel fuel container on the
ground when transferring the diesel fuel from
the pump to the container. Hold the hose nozzle
firmly against the side of the container while
filling it. This prevents static electri city buildup
which could cause sparks and ignite fuel
vapors.
NEVER place diesel fuel or other flammable
material such as oil, hay or dried grass close to
the engine during engine operation or shortly
after shutdown.
Failure to compl y will result in death or serious
injury.
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
NEVER use diesel fuel as a cleaning agent.
Failure to compl y will result in death or serious
injury.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 31
DANGER
CRUSH HAZARD!
When you need to transport an engine for repair,
have a helper assist you to attach it to a hoist
and load it on a truck.
NEVER stand under a hoisted engine. If the
hoist mechanism fails, the engine will fall on
you, causing death or seri ou s injury.
Failure to compl y will result in death or serious
injury.
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
When you remove any fuel system component
to perform mainten ance ( such as changing the
fuel filter) place an approved container under
the opening to catch the fuel.
NEVER use a shop rag to catch the fuel. Vapors
from the rag are flammable and explosive.
Wipe up any spills immediately.
Wear eye protection. The fuel system is under
pressure and fuel could spray out when you
remove any fuel system co mpon ent.
Failure to compl y will result in death or serious
injury.
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
Place an approved container under the air bl eed
port when you prime the f uel system. Never use
a shop rag to catch the fuel. Wipe up any spills
immediately. ALWAYS close the air bleed port
after you complete pri min g the system.
Wear eye protection. The fuel system is under
pressure and fuel could spray out when you
open the air bleed port.
If the unit has an electric fuel pump, turn the
key switch to the ON position for 10 to 15
seconds, or until the fuel coming out of the air
bleed port is free of bubbles, to allow the
electric fuel pump to pri me the syst em.
If the unit has a mechanical fuel pump, operate
the fuel priming pump several times until the
fuel coming out of the air bleed port is free of
bubbles.
Failure to compl y will result in death or serious
injury.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 32
WARNING
EXHAUST HAZARD!
NEVER operate the engine in an enclosed area
such as a garage, tunnel, underground room,
manhole or ship’s hold without proper
ventilation.
NEVER block windows, vents, or other means
of ventilation if the engine is operating in an
enclosed area. All intern al combust ion engines
create carbon monoxide gas during operation.
Accumulation of this gas within an enclosure
could cause illness or even death.
Make sure that all connections are tigh tened to
specifications after repair is made to the
exhaust system.
Failure to comply could result in death or
serious injury.
WARNING
SEVER HAZARD!
Keep hands and other body parts away from
moving/rotating parts such as the cooling fan,
flywheel or PTO shaft .
Wear tight-fitting clothing and keep your hair
short or tie it back whil e the engine is running.
Remove all jewelry before you operate or
service the machine.
NEVER start the engine in gear. Sudden
movement of the engine and/or machin e could
cause death or serious personal injury.
NEVER operate the engine without the guards
in place.
Before you start the engine make sure that all
bystanders are cl ear of th e area.
Keep children and pets away while the engine is
operating.
Check before starting the engin e that any tools
or shop rags used during maintenance have
been removed from th e area.
Failure to comply could result in death or
serious injury.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 33
WARNING
SUDDEN MOVEMENT HAZARD!
Engaging the transmission or PTO at an
elevated engine speed could result in
unexpected movement of the equ ipment.
Failure to comply could result in death or
serious injury.
WARNING
BURN HAZARD!
Keep your hands and other body parts away
from hot engine surfaces such as the muffler,
exhaust pipe, turbocharger (if equipped) and
engin e block during op eration and sho rtly after
you shut the engine down. These surfaces are
extremely hot wh ile the engin e is operating an d
could seriously burn you.
Failure to comply could result in death or
serious injury.
WARNING
ALCOHOL AND DRUG HAZARD!
NEVER operate the engine while you are under
the influe nc e of alcohol or drugs.
NEVER operate the engine when you are feeling
ill.
Failure to comply could result in death or
serious injury.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 34
WARNING
EXPOSURE HAZARD!
Wear personal protective equipment such as
gloves, work shoes, eye and hearing prot ection
as required by the task at hand.
NEVER wear jewelry, unbuttoned cuffs, ties or
loose-fitting clothing when you are working
near moving/rot ating parts such as the cool ing
fan, flywheel or PTO sh af t.
ALWAYS tie back long hair when you are
working near moving/rotating parts such as a
cooling fan, flywheel, or PTO shaft.
NEVER operate the engine while wearing a
headset to listen to music or radio because it
will be difficult to hear the alert signals.
Failure to comply could result in death or
serious injury.
WARNING
BURN HAZARD!
Batteries contain sulfuric acid. NEVER allow
battery fluid to come in contact with clothing,
skin or eyes. Severe burns could result.
ALWAYS wear safety goggles and protective
clothing when servicing the battery. If battery
fluid contacts the eyes and / or skin,
immediatel y flush the affected area with a large
amount of clean water and obtain prompt
medical treatment.
Failure to comply could result in death or
serious injury.
WARNING
HIGH-PRESSURE HAZARD!
Avoid skin contact with the high-pressure
diesel fuel spray caused by a fuel system leak
such as a broken fuel injection line. Highpressure fuel can penetrat e your skin and result
in serious injury. If you are exposed to highpressure fuel spray, obtain prompt medical
treatment.
NEVER check for a fuel leak with your hands.
ALWAYS use a piece of wood or cardboard.
Have your authorized Yanmar industri al engine
dealer or distributor repair the damage.
Failure to comply could result in death or
serious injury.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 35
WARNING
SHOCK HAZARD!
Turn off the battery switch (if equipped) or
disconnect the negative battery cable before
servicing the electrical system.
Check the electrical harnesses for cracks,
abrasions, and damaged or corroded
connectors. ALWAYS keep t he connectors and
terminals cl ean.
Failure to comply could result in death or
serious injury.
WARNING
ENTANGLEMENT HAZARD!
Stop the engine before you begi n to servi ce it.
NEVER leave the key in the key switch when
you are servicing the engine. Someone may
accidentally st art the engin e and not reali ze you
are servicing it. This could result in a serious
injury.
If you must service the engine while it is
operating, remo ve all jewel ry, tie back long hair,
and keep your hands, other body parts and
clothing away from moving/rotating parts.
Failure to comply could result in death or
serious injury.
WARNING
BURN HAZARD!
If you must drain the engine oil while it is still
hot, stay clear of the hot engine oil to avoid
being bur ne d.
ALWAYS wear eye protection .
Failure to comply could result in death or
serious injury.
WARNING
BURN HAZARD!
Wait until the engine cools before you drain the
engine coolant . Hot engine coolant may splash
and burn y ou .
Failure to comply could result in death or
serious injury.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 36
CAUTION
COOLANT HAZARD!
Wear eye protection and rubber gloves when
you handle long life or extended life engine
coolant. If contact with th e eyes or skin should
occur, flush eyes and wash immediately with
clean water.
Failure to comply may result in minor or
moderate injury.
CAUTION
FLYING OBJECT HAZARD!
ALWAYS wear eye protection when servicing
the engine and when using compressed air or
high-pressure water. Dust, flying debris,
compressed air, pressurized water or steam
may injure your eyes.
Failure to comply may result in minor or
moderate injury.
CAUTION
Only use di esel fuels recommended by Y anmar
for the best engine performance, to prevent
engine damage and to comply with EPA/ARB
warranty requirements.
Only use clean diesel fuel.
NEVER remove the primary strainer (if
equipped) from the fuel tank filler port. If
removed, dirt and debris could get into the fuel
system causing it to clog.
CAUTION
Only use the engine oil specified. Other engine
oils may affect warranty coverage, cause
internal engine components to seize and / or
shorten engine life.
Prevent dirt and debris from contaminat ing the
engine oil. Carefully clean the oil cap/dipstick
and the surrounding area before you remove
the cap.
NEVER mix different types of engine oil. This
may adversely affect the lubricating properties
of the engine oil.
NEVER overfill. Overfilling may result in white
exhaust smoke, engine overspeed or internal
damage.
CAUTION
Only use the engine coolant specified. Other
engine coolants may affect warranty coverage,
cause an internal buildup of rust and scale
and/or shorten engine life.
Prevent dirt and debris from contaminat ing the
engine coolant . Carefully clean the radiat or cap
and the surrounding area before you remove
the cap.
NEVER mix different types of engine coolants.
This may adversely aff ect the properties of the
engine coolant.
CAUTION
NEVER attempt to modify the engine’s design
or safety features such as defeating th e engine
speed limit control or the diesel fuel injection
quantity control.
Modifications may impair the engine’s safety
and performance characteristics and shorten
the engine’s life. Any alterations to this engine
may void its warranty. Be sure to use Yanmar
genuine replacement parts.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 37
CAUTION
Observe the following environmental operating
conditions to maintain engine performance and
avoid premature engi ne wear:
• Avoid operating in extremel y du st y con ditions.
• Avoid operating in th e presen ce of chemical
gases or fumes.
• Avoid operating in a corrosive atmosphere
such as salt water spray.
• NEVER install the engine in a floodplain
unless proper precautions are taken to avoid
being su bject to a flood.
• NEVER expose the engine to the rain.
CAUTION
Observe the following environmental operating
conditions to maintain engine performance and
avoid premature engi ne wear:
• The standard range of ambient temperatures
for the normal operation of Yanmar engines is
from +5°F (-15°C) to +113°F (+45°C).
• If the ambient temperature exceeds +113°F
(+45°C) the engin e may overh eat and cause
the engine oil to break down.
• If the ambient temperature is below +5°F (-
15°C) the engine will b e hard to start and the
engine oil may not flow easily.
• Contact your authorized Yanmar industrial
engine dealer or distributor if the engine will
be operated outside of this standard
temperature range.
CAUTION
NEVER hold the key in the START position for
longer than 15 seconds or the starter moto r will
overheat.
CAUTION
For maximum engine life, Yanmar recommend s
that when shutting the engine down, you allow
the engine to idle, without load, for five minutes.
This will allow the engine components that
operate at high temperatures, such as the
turbocharger (i f equipped) and exhaust system,
to cool slightly before the engine itself i s shut
down.
CAUTION
NEVER use an engine starting aid such as ether.
Engine damage will result.
CAUTION
Make sure the engine is installed on a level
surface. If a continuously running engine is
installed at an angle greater than (IDI = 25°, DI =
30°) in any direction or if an engine runs for
short periods o f time (less than three minutes)
at an angle great er than (IDI = 30°, DI = 35°) in
any direction, engine oil may enter the
combustion chamb er causing excessive engine
speed and white exhaust smoke. This may
cause serious engine damage.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 38
CAUTION
New Engine Break-in:
• On the initial engine start-up, allow the engine
to idle for approxi mat ely 15 minutes while you
check for proper engine oi l p ressure, diesel
fuel leaks, engine oil leaks, coolant leaks, and
for proper operation of the indicators and/or
gauges.
• During the first hou r of operati on, vary the
engine speed and the load on the engine.
Short periods of maximum engine speed and
load are desirable. Avoid prolonged operation
at minimum or maximum engin e speed s and
loads for the next fou r to five hou rs.
• During the break-in peri od , carefully observe
the engine oil pressure and engine
temperature.
• During the break-in peri od , ch eck the engine
oil and coolant level s f requ ently.
CAUTION
NEVER engage the starter motor while the
engine is running. This may damage the starter
motor pinion and/or ring gear.
CAUTION
It is important to perfo rm dai ly checks.
Periodic maintenance prevents unexpected
downtime, reduces th e nu mber of accidents due
to poor machine performance and helps extend
the life of the engine.
CAUTION
ALWAYS be environmentally responsible.
Follow the guidelines of the EPA or other
governmental agencies for the proper disposal
of hazardous materials such as engine oil,
diesel fuel and engine coolant. Consul t th e local
authoriti es or reclamation facility.
NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground, or into ground water or waterways.
Failure to follow these procedures may
seriously harm the en viron ment.
CAUTION
Protect the air cleaner, turbocharger (if
equipped) and electric components from
damage when you use steam or high-pressure
water to clean the engine.
CAUTION
NEVER overfill the engine with engine oil.
ALWAYS keep the oil level between the upper
and lower lines on the oil cap/d ipstick.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 39
CAUTION
NEVER use high-pressure w ater or co mpressed
air at greater than 28 psi (193 kPa; 19 686
mmAq) or a wire brush to clean the radiator fins.
Radiator fins damage easily.
CAUTION
NEVER attempt to adjust the low or high idle
speed limit screw. This may impair the safety
and performance of the machine and short en its
life. If the idle speed limit screws require
adjustment, see your authorized Yanmar
industrial engine dealer or distributor.
CAUTION
Establish a periodic maintenance plan
according to the engine application and make
sure you perform the required periodic
maintenance at the intervals indicated. Failure
to follow these guidelines will impair the
engine’s safet y and p erf ormance characteristics,
shorten the engine’s life and may affect the
warranty coverag e on your eng in e.
See Yanmar Limited Warranty in Warranty
Section.
Consult your authorized Yanmar dealer or
distributor fo r assistance when checking items
marked with a.
CAUTION
If the fuel filter/water separator is positioned
higher than the fuel level in the fuel tank, water
may not drip out when the fuel filter/water
separator d rain co ck is op ened. I f thi s happ ens,
turn the air vent screw on the top of the fuel
filter/water separator 2-3 turns
counterclockwise.
Be sure to tighten the air vent screw after the
water has dr a ined out.
CAUTION
When the engine is operated in dusty
conditions, clean the air cleaner element more
frequently.
NEVER operate the engine with the air cleaner
element(s) removed. This may allow foreign
material to enter th e engine and damage it.
CAUTION
The maximum air int ake restriction, in terms o f
differential pressure measurement, must not
exceed 0.90 psi ( 6.23 kPa; 635 mmAq). Clean or
replace the ai r cleaner element if the air intake
restriction exceed s t he above mentioned value.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 40
Introduction
This section of the Servic e M anual descr ibes the
procedures for proper care and maintenance of the
engine.
The Importance of Periodic
Maintenance
Engine deterioration and wear occurs in proportion
to length of time the engine has been i n service and
the conditions the engine is subject to during
operation. P eri odic m aintenance prevents
unexpected downtime, reduces the number of
accidents due to poor machine performance and
helps extend the life of the engi ne.
Performi ng Periodic Maintenance
WARNING
EXHAUST HAZARD!
NEVER operate the engine in an enclosed area
such as a garage, tunnel, underground room,
manhole or ship’s hold without proper
ventilation.
NEVER block windows, vents, or other means
of ventilation if the engine is operating in an
enclosed area. All intern al combust ion engines
create carbon monoxide gas during operation.
Accumulation of this gas within an enclosure
could cause illness or even death.
Make sure that all connections are tigh tened to
specifications after repair is made to the
exhaust system.
Failure to comply could result in death or
serious injury.
Perform periodic maintenance procedures in an
open, level area free f r om tr affic. If possibl e,
perform the proc edur es i ndoors to prevent
environmental condi tions, such as rain, wind, or
snow, from damaging the machine.
Yanmar Replacement Parts
Yanmar recommends that you use genuine Yanmar
parts when replacement parts are needed. Genuine
replacement parts help ensure l ong engine life.
Required EPA / ARB Maintenance-USA
Only
To maintain optimum engi ne performance and
compliance with the Environmental Protection
Agency (EPA) Regulations Non-road Engines and
the California Air Resources Board (ARB,
Californi a), it is essential that you follow the
Periodic Maint enanc e S c hedule on page 41 and
Periodic Maint enanc e P r oc edur es on page 43.
EPA / ARB Installation RequirementsUSA Only
The following are the installation requirem ents for
the EPA / ARB. Unless these requirements are met,
the exhaust gas emissions wi ll not be within the
limits specified by t he EPA and ARB.
Maximum Exhaust Gas Restriction shall be:
• 4TNV98 : 2.22 psi (15.3 kPa; 1560mm Aq) or
Iess
• 4TNE98 : 8.53 psi (58.8 kPa; 6000mm Aq)
Maximum air intake restriction shall be 0.90 psi
(6.23 kPa; 635 mm Aq) or less. Clean or replace
the air cleaner elem ent if the air intake restriction
exceeds the abov e mentioned v alue.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 41
Periodic Maintenance Schedule
Daily and periodic m aintenance is important to keep
the engine in good operating condition. The
following is a summ ary of maint enanc e items by
periodic mai ntenance intervals. Periodic
maintenance int ervals vary depending on engine
applicati on, loads, diesel fuel and engine oil used
and are hard to establish definitively. The following
should be treated onl y as a general guideline.
CAUTION
Establish a periodic maintenance plan
according to the engine application and make
sure you perform the required periodic
maintenance at the intervals indicated. Failure
to follow these guidelines will impair the
engine’s safet y and p erf ormance characteristics,
shorten the engine’s life and may affect the
warranty coverag e on your eng in e.
See Yanmar Limited Warranty in Warranty
Section.
Consult your authorized Yanmar dealer or
distributor fo r assistance when checking items
marked with a.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 42
○:Check ◇:Replace
Periodic Maintenance Interval
System Check Item
Daily
Every
50
hours
Every
250
hours
Every
500
hours
Every
1000
hours
Every
1500
hours
Every
2000
hours
Check and Refill Engine Cool ○
Check and Clean Radiator Fins ○
Check Engine Coolant Temp.
Indicator
○
Check and Adjust Cooling Fan V-Belt
○1st
time
○
2nd
and
after
Cooling
System
Drain, Flush and Refill Cooling
System with New Coolant
◇ or
every year
whichever
comes first
Adjust Intake / Exhaust Valve
Clearance
○
Cylinder
Head
Lap Intake / Exhaust Valve Seats ○
Check Indicators ○
Electrical
Equipment
Check Battery ○
Check Engine Oil Level ○
Check Engine Oil Pressure Indicator ○
Drain and Fill Engine Oil
Engine Oil
Replace Engine Oil Filter
◇1st
time
◇
2nd
and
after
Engine
Speed
Control
Check and Adjust Governor Lever
and Engine Speed Control
○ ○
Inspect, Clean and Test Fuel Injectors ○
Emission
Control
Warranty
Inspect Crankcase Breather System ○
Check and Refill Fuel Tank Level ○
Check Fuel Filter Indicator ○
Drain Fuel Tank ○
Drain Fuel Filter / Water Separator ○
Check Fuel Filter / Water Separator ○
Clean Fuel Filter / Water Separator ○
Fuel
Replace Fuel Filter ◇
Hoses
Replace Fuel System and Cooling
System Hoses
○ or
every 2
years
Intake and
Exhaust
Clean or Replace Air Cleaner Element ○ ◇
Complete
Engine
Overall Visual Check Daily ○
NOTE: These procedures are consider ed nor mal maintenance and are performed at the owner’s expense.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 43
Periodic Maintenance Procedures
Daily
Perform the following procedures daily.
• Drain Fuel F ilt er / Wate r Separator
• Check Fuel Hoses and Engine Cool ant Hoses
Drain Fuel Filter / Water Separator
DANGER
FIRE AND EXPLOSION HAZARD!
• Diesel fuel is extremely flammabl e and
explosive under certain conditions.
• When you remove any fuel system component
to perform maintenance (such as changing the
fuel filter) place an approved container under
the opening to catch the fuel.
• NEVER use a shop rag to catch the fuel. Vapors
from the rag are extremely fl ammable and
explosive.
• Wipe up any spills immediately.
• Wear eye protection. The fuel system is under
pressure and fuel could spray out when you
remove any fuel system co mpon ent.
• Failure to comply will result in death or serious
injury.
0000009en.
4TNE98 For D25S-5 Only
WARNING
HIGH PRESSURE HAZARD!
• Avoid skin contact with high pressure diesel
fuel spray caused by a fuel system leak such as
a broken fuel injecti on line. High pressure fuel
can penetrate your skin and result in serious
injury. If you are exposed to high pressure fuel
spray obtain prompt medical treat ment.
• NEVER check for a fuel leak with your hands.
ALWAYS u se a pi ece of wood or cardboard.
Have your authorized Yanmar industrial engin e
dealer or distributor repair the damage.
• Failure to comply could resu lt in death or
serious injury .
0000008en.
CAUTION
If no water drips when the fuel filter/water
separator drain cock is opened, loosen the air
vent screw on the top of the fuel filter/water
separator by using a screwdriver to turn it
counterclockwi se 2-3 turn s.This may occur if the
fuel filter / water separator is positioned higher
than the fuel level in the fuel tan k. After draining
the fuel filter/w ater separator, be sure to tighten
the air vent screw.
0000025en.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 44
CAUTION
Be responsible to the environment.
Follow these procedures for hazardous waste
disposal. Failu re to follow these p rocedu res may
seriously harm the en viron ment.
• Follow the guidelines of the EPA or other
governmental agency for the proper di sposal of
hazardous materi als such as engine oil, diesel
fuel and engine cool ant. Consult the local
authoriti es or reclamation facility.
• NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground or into ground w at er or waterw ays.
0000013en.
NEVER wait until the scheduled periodic
maintenance if the fuel filter indicator comes on.
The fuel filter / water separator c ontains a sensor to
detect the amount of water and contaminants. This
sensor sends a signal to an indic ator to alert the
operator.
Drain the fuel filt er / water separator as follows:
Figure 5-1
1. Position an approved container under the fuel
filter / water separator (Figure5-1, (1)) to collect
the contaminants.
2. Loosen the drain cock (Figure5-1, (2)) at the
bottom of the fuel filter / water separator. Drain
any water collected insi de.
3. Hand tighten the dr ain c oc k.
4. Be sure to prime the diesel fuel system when you
are done. See Priming t he Fuel Sy stem on
page15.
Check Fuel Hoses and Engine Coolant
Hoses
Daily check the fuel system and engine coolant
system hoses. If they are cracked or degraded,
replace them.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 45
Daily
After Initial 50 Hours of Operation
Perform the following maintenance after the initial
50 hours of operation.
• Replace Engine Oil and Engine Oil Filter
• Check and Adjust Cooling Fan V-Belt
Replace Engine Oil and Engine Oil Filter
WARNING
BURN HAZARD!
If you must drain the engine oil while it is still
hot, stay clear of the hot engine oil to avoid
being bur ne d.
ALWAYS wear eye protection .
Failure to comply could result in death or
serious injury.
WARNING
SUDDEN MOVEMENT HAZARD!
Engaging the transmission or PTO at an
elevated engine speed could result in
unexpected movement of the equ ipment.
Failure to comply could result in death or
serious injury.
CAUTION
Only use the engine oil specified. Other engine
oils may affect warranty coverage, cause
internal engine components to seize and / or
shorten engine life.
Prevent dirt and debris from contaminat ing the
engine oil. Carefully clean the oil cap/dipstick
and the surrounding area before you remove
the cap.
NEVER mix different types of engine oil. This
may adversely affect the lubricating properties
of the engine oil.
NEVER overfill. Overfilling may result in white
exhaust smoke, engine overspeed or internal
damage.
CAUTION
ALWAYS be environmentally responsible.
Follow the guidelines of the EPA or other
governmental agencies for the proper disposal
of hazardous materials such as engine oil,
diesel fuel and engine coolant. Consul t th e local
authoriti es or reclamation facility.
NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground, or into ground water or waterways.
Failure to follow these procedures may
seriously harm the en viron ment.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance
46
The engine oil in a new engine becomes
contaminated fr om the initial break-in of internal
parts. It is very important that t he initial oil and filter
change is performed as scheduled.
NOTE: The oil drain plug may be in another
location if an optional oil pan is used.
Drain the engine oil as follows:
1. Make sure the engine is level.
2. Start the engine and bring it up to operating
temperature.
3. Stop the engine.
4. Remove one of the oil filler caps (Figure 5-1, (1))
to vent the engine cr ank c ase and all ow the
engine oil to drai n more easily.
5. Position a container under the engine to collect
waste oil.
Figure 5-1
6. Remove the oil drain plug (Figure 5-2, (1)) from
the engine oil pan. Allow oil to drain.
7. After all oil has been drained from the engine,
reinstall the oil drain plug (Figure 5-2, (1)) and
tighten to 139.8 - 47.0 ft·lb ( 53.9 - 63.7 N·m; 5. 5
- 6.5 kgf·m).
8. Dispose of used oil proper ly.
Remove the engine oil filter as follows:
1. Turn the engine oil filter (Figure 5-2, (2) )
counterclockwise (Figure 5-2, (3)) using a filter
wrench.
Figure 5-2
2. Clean the engine oil filter mounting face.
3. Lightly coat the gasket on the new oil filter with
engine oil. Install t he new engine oil filter
manually by turning it clockwise (F igure 5-2, (4))
until it contacts the mounting surface. Tighten to
14 - 17 ft·lb (19.6 - 23.5 N·m; 2.0 - 2.4 kgf·m ) or
one additional turn using the filter wrench.
Applicable Engine Oil Filter Part No.
4TNV98 A408065
4TNE98 A408065
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 47
4. Add new engine oil to the engine as specified in
Adding Engine Oil on page 17.
CAUTION
NEVER overfill the engine with engine oil.
ALWAYS keep the oil level between the upper
and lower lines on the oil cap/d ipstick.
5. Warm up the engine by running it for five minutes
and check for any engine oil leaks.
6. After engine is warm, shut it off and let it sit for 10
minutes.
7. Recheck the engine oil level.
8. Add engine oil (Figure 5-3, (5)) as needed until
the level is between the upper (Figure 5-3, (2))
and lower lines (Figure 5-3, (3)) shown on the
dipstick (Figure 5-3, (1)).
Figure 5-3
9. Reinstall the oil fill er c ap (Figu re 5- 3, (4)). If any
engine oil is spilled, wipe it away with a clean
cloth.
Check and Adjust Cooling Fan V-Belt
The V-belt will slip if it does not have the proper
tension. This will prevent the alternator from
generating suffici ent power. Also, the engine will
overheat due to the engine c oolant pump pulley
slipping.
Check and adjust the V-belt tension (deflec tion) as
follows:
1. Press the V-belt down with your thumb with a
force of approxim ately 22 ft·lb (98 N·m; 10 kgf) to
check the deflection.
There are three positions to check for V-belt
tension (Figure 5-4, (A), (B) and (C)). You can
check the tension at whichever position is the
most accessible. The proper deflection of a used
V-belt at each position is:
Used V-Belt Tension
A B C
3/8 - 1/2 in.
(10 - 14 mm)
1/4 - 3/8 in.
(7 - 10 mm)
5/16 - 1/2 in.
(9 - 13 mm)
NOTE: A “Used V-Belt” refers to a V-belt which has
been used on a running engine for five minutes or
more.
Figure 5-4
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance
48
2. If necessary, adjust the V-belt tension. Loosen
the adjusting bolt (Figure 5-5, (1)) and move the
alternator (Figure 5-5, (2)) with a pry bar (Figure
5-5, (3)) to tight en the V-belt to the desired
tension. Then tighten the adjusting bolt.
Figure 5-5
3. Tighten the V-belt to the proper tension. There
must be clearance (Fig ure 5-6, (1)) between the
V-belt and the bottom of the pulley groove. If
there is no clearance ( Fi gu re 5- 6, (2) ) between
the V-belt and the bottom of the pulley groove,
replace the V-belt.
Figure 5-6
4. Check the V-belt for cracks, oil or wear. If any of
these conditi ons exist, replace the V-belt.
5. Install the new V-belt. Refer to the table for
proper tension.
New V-Belt Tension
A B C
5/16 - 7/16 in.
(8 - 12 mm)
3/16 - 5/16 in.
(5 - 8 mm)
1/4 - 7/16 in.
(7 - 11 mm)
6. After adjusting, run the engine for 5 minutes or
more. Check the tension again using the
specifications for a used V-belt.
Used V-Belt Tension
A B C
3/8 - 1/2 in.
(10 - 14 mm)
1/4 - 3/8 in.
(7 - 10 mm)
5/16 - 1/2 in.
(9 - 13 mm)
Every 50 Hours of Operation
After you complete the initi al 50 hour m aintenance
procedures, perf orm the following procedures every
50 hours thereafter.
• Drain Fuel F ilt er / Wate r Separator
• Check Battery
Drain Fuel Filter / Water Separator
4TNV98 & 4TNE98 (For China) Engin e
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
When you remove any fuel system component
to perform mainten ance ( such as changing the
fuel filter) place an approved container under
the opening to catch the fuel.
NEVER use a shop rag to catch the fuel. Vapors
from the rag are flammable and explosive.
Wipe up any spills immediately.
Wear eye protection. The fuel system is under
pressure and fuel could spray out when you
remove any fuel system co mpon ent.
Failure to compl y will result in death or serious
injury.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 49
CAUTION
If the fuel filter / water separator is positioned
higher than the fuel level in the fuel tank, water
may not drip out when the fuel filter / water
separator d rain co ck is op ened. I f thi s happ ens,
turn the air vent screw on the top of the fuel
filter / water separator 2-3 turns
counterclockwise.
Be sure to tighten the air vent screw after the
water has dr a ined out.
CAUTION
ALWAYS be environmentally responsible.
Follow the guidelines of the EPA or other
governmental agencies for the proper disposal
of hazardous materials such as engine oil,
diesel fuel and engine coolant. Consul t th e local
authoriti es or reclamation facility.
NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground, or into ground water or waterways.
Failure to follow these procedures may
seriously harm the en viron ment.
Drain the fuel filt er / water separator whenever
there are contaminants, such as water, collected in
the bottom of the cup. NEVER wait until the
scheduled periodic maintenance if contaminants
are discovered.
The cup of the separator is made fr om semitransparent material. In the cup is a red colored
float ring. The float ring will ri se to the surface of the
water to show how much needs to be drained. Also,
some optional f uel filt er / water separator s are
equipped with a sensor to det ec t t he am ount of
contaminants. This sensor sends a signal t o an
indicator t o alert the operator.
Drain the fuel filt er / water separator as follows:
1. Position an approved container under the fuel
filter / water separator (Figure 5-7, (1)) to collect
the contaminants.
Figure 5-7
2. Close (Figure 5-7, (2)) the fuel cock (Figure 5-7,
(3)).
3. Loosen the drain cock (Figure 5-7, (4)) at the
bottom of the fuel filter / water separator. Drain
any water collected insi de.
4. Hand-tighten the drain cock.
CAUTION
If the fuel filter/water separator is positioned
higher than the fuel level in the fuel tank, water
may not drip out when the fuel filter/water
separator d rain co ck is op ened. I f thi s happ ens,
turn the air vent screw on the top of the fuel
filter/water separator 2-3 turns
counterclockwise.
Be sure to tighten the air vent screw after the
water has dr a ined out.
5. Open the fuel cock (Figure 5-7, (3)).
6. Be sure to prime the diesel fuel system when you
are finished. See Priming the Fuel System on
page 15.
7. Check for leaks.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance
50
Check Battery
DANGER
EXPLOSION HAZARD!
NEVER check the remaining battery charge by
shorting out the terminals. This will result in a
spark and may cause an explosion or fire. Use a
hydrometer to check the remaining battery
charge.
If the electrolyte is frozen, slowly warm the
battery before you recharge it.
Failure to compl y will result in death or serious
injury.
WARNING
BURN HAZARD!
Batteries contain sulfuric acid. NEVER allow
battery fluid to come in contact with clothing,
skin or eyes. Severe burns could result.
ALWAYS wear safety goggles and protective
clothing when servicing the battery. If battery
fluid contacts the eyes and / or skin,
immediatel y flush the affected area with a large
amount of clean water and obtain prompt
medical treatment.
Failure to comply could result in death or
serious injury.
CAUTION
ALWAYS be environmentally responsible.
Follow the guidelines of the EPA or other
governmental agencies for the proper disposal
of hazardous materials such as engine oil,
diesel fuel and engine coolant. Consul t th e local
authoriti es or reclamation facility.
NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground, or into ground water or waterways.
Failure to follow these procedures may
seriously harm the en viron ment.
When the amount of fluid near s the lower limit
(Figure 5-8, (1) ), fill with distilled water (Figure 5-8,
(2)) so it is at the upper limit (Figure 5-8, ( 3)). If
operation conti nues with insufficient batter y fluid,
the battery life is shortened, and the battery may
overheat and explode. During the summer, check
the fluid level more often than specified.
Figure 5-8
If the engine cranki ng speed i s so slo w that the
engine does not start, recharge the battery.
If the engine still will not start after charging, have
your authoriz ed Yanmar industrial engine dealer or
distribut or check the bat tery and the engine’s
starting system.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 51
If operating t he machine where the ambient
temperature could drop to 5°F (-15°C) or less,
remove the battery from the m ac hine at the end of
the day. Store the batt er y in a warm place until the
next use. This will help start t he engine easi ly at low
ambient temperatures.
Every 250 Hours of Operation
Perform the following maintenance every 250 hours
of operation.
• Drain Fuel Tank
• Check and Clean Radiat or Fins
• Check and Adjust Cooling Fan V-Belt
• Check and Adjust the Governor Lever and Engine
Speed Control
• Clean Air Cleaner Element
Drain Fuel Tank
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
When you remove any fuel system component
to perform mainten ance ( such as changing the
fuel filter) place an approved container under
the opening to catch the fuel.
NEVER use a shop rag to catch the fuel. Vapors
from the rag are flammable and explosive.
Wipe up any spills immediately.
Wear eye protection. The fuel system is under
pressure and fuel could spray out when you
remove any fuel system co mpon ent.
Failure to compl y will result in death or serious
injury.
CAUTION
ALWAYS be environmentally responsible.
Follow the guidelines of the EPA or other
governmental agencies for the proper disposal
of hazardous materials such as engine oil,
diesel fuel and engine coolant. Consul t th e local
authoriti es or reclamation facility.
NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground, or into ground water or waterways.
Failure to follow these procedures may
seriously harm the en viron ment.
Note that a typical fuel tank is illustrated.
1. Position an approved container under the diesel
fuel tank (Figure 5-9, (1)) to collect the
contaminates.
2. Remove the fuel cap (Figu re 5- 9, ( 3) ).
3. Remove the drain plug (Fig ure 5-9, (2)) of the
fuel tank to drain the contaminates (water, dirt,
etc.) from the bottom of t he tank.
Figure 5-9
4. Drain the tank until clean diesel fuel with no
water and dirt flows out. Reinstall and tighten the
drain plug firmly.
5. Reinstall the fuel cap.
6. Check for leaks.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance
52
Check and Clean Radiator Fins
CAUTION
FLYING OBJECT HAZARD!
ALWAYS wear eye protection when servicing
the engine and when using compressed air or
high-pressure water. Dust, flying debris,
compressed air, pressurized water or steam
may injure your eyes.
Failure to comply may result in minor or
moderate injury.
Dirt and dust adhering t o the radiator fins reduce
the cooling perf ormance, causing overheating.
Make it a rule to check the radiat or fins daily and
clean as needed.
Note that a typical radiator is shown in Figure 5-10
for illustrative purposes only.
• Blow off dirt and dust from fins and radiator with
28 psi (0.19 MPa; 2 kgf/cm²) or less of
compressed air (Fi gu re 5- 10, (1)). Be careful not
to damage the fins with t he compressed air.
• If there is a large amount of contamination on the
fins, apply deter gent, thoroughly clean and ri nse
with tap water.
CAUTION
NEVER use high-pressure w ater or co mpressed
air at greater than 28 psi (193 kPa; 19 686
mmAq) or a wire brush to clean the radiator fins.
Radiator fins damage easily.
Figure 5-10
Check and Adjust Cooling Fan V-Belt
Check and adjust the cooling fan V-belt every 250
hours of operation after the init ial 50 hour V-belt
maintenance. See Check and Adjust Cooling Fan
V-Belt on page 47.
Check and Adjust the Governor Lever and
Engine Speed Control
The governor lev er and engi ne speed cont rol
(throttle lev er, pedal, etc.) of the machine are
connected together by a throttle cable or rod. If the
cable becomes stretched, or the connections
loosen, the gov er nor l ev er may not r espond to
change of engine speed control position. This may
make operation of t he machine unsafe. Check the
cable periodic ally and adjust if necessary.
NEVER force the throttle cable or pedal to move.
This may deform the gov ernor lever or stretch the
cable and cause irregular operation of the engine
speed control.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 53
Checking and adjusting the governor lever:
1. Check that the gover nor lev er (Figure 5-11, (1))
makes uniform contact with the high idle (Figure
5-11, (2)) and low idle (Figure 5-11, (3)) speed
limit screws when the engine speed c ontrol is in
the high idle speed or low idle speed position.
4TNV98 ENGINE
4TNE98 ENGINE
Figure 5-11
2. If the governor lev er does not make contact with
the high idle or low idl e speed limit screw, adjust
the throttl e cabl e.
3. In some engine speed control applications,
loosen the throttle cable lock nut (Figure 5-11,
(4)) and adjust the cable so the governor lev er
makes proper contact with the high / low idle
speed limit screw.
CAUTION
NEVER attempt to adjust the low or high idle
speed limit screw. This may impair the safety
and performance of the machine and short en its
life. If the idle speed limit screws require
adjustment, see your authorized Yanmar
industrial engine dealer or distributor.
Clean Air Cleaner Element
Note that a typical air cl eaner is shown in Figure 5-
12 and Figure 5-13 for illustrative purposes only.
The engine performance is adversely affected when
the air cleaner elem ent is clogged with dust.
Be sure to clean the air filter element periodically.
1. Unlatch and remove the air cleaner cover
(Figure 5-12, (1) ) .
Figure 5-12
2. Remove the element (Figure 5-12, (2)) (outer
element if equipped with two elements).
CAUTION
FLYING OBJECT HAZARD!
ALWAYS wear eye protection when servicing
the engine and when using compressed air or
high-pressure water. Dust, flying debris,
compressed air, pressurized water or steam
may injure your eyes.
Failure to comply may result in minor or
moderate injury.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance
54
3. Blow air (Figure 5- 12, (3) ) through the element
from the inside out using 42-71 psi (0.29-
0.49MPa; 3.0- 5.0 kgf/ cm²) compressed air to
remove the particul ates. Use the lowest possible
air pressure to remove the dust without
damaging the element.
4. If the air cleaner is equi pped with a double
element, only remov e and r eplac e the inner
element (Fig ure 5-13, (1)) if the engine lacks
power or the dust indicator actuates (if equi pped).
Figure 5-13
5. The inner element should not be r em ov ed when
cleaning or repl aci ng the outer element. The
inner element is used to prevent dust from
entering the engine while servicing the outer
element.
6. Replace the elem ent wit h a new one if the
element is damaged, exc essively dirty or oily.
7. Clean inside of the air cl eaner c ov er.
8. Install the element i nto t he air cl eaner c ase
(Figure 5-12, (4) ) .
9. Reinstall the air cl eaner cover making sure you
match the arrow (Figu re 5- 12, (5)) on the cover
with the arrow on the case (Fig ure 5-12, (6)).
10. Latch the air cleaner cover to the case.
CAUTION
When the engine is operated in dusty
conditions, clean the air cleaner element more
frequently.
NEVER operate the engine with the air cleaner
element(s) removed. This may allow foreign
material to enter th e engine and damage it.
Every 500 Hours of Operation
Perform the following maintenance every 500 hours
of operation.
• Replace Engine Oil and Engine Oil Filter
• Replace Air Cleaner Element
• Replace Fuel Filt er
• Clean Fuel Filter / Water Separator
Replace Engine Oil and Engine Oil Filter
CAUTION
Only use the engine oil specified. Other engine
oils may affect warranty coverage, cause
internal engine components to seize and / or
shorten engine life.
Prevent dirt and debris from contaminat ing the
engine oil. Carefully clean the oil cap/dipstick
and the surrounding area before you remove
the cap.
NEVER mix different types of engine oil. This
may adversely affect the lubricating properties
of the engine oil.
NEVER overfill. Overfilling may result in white
exhaust smoke, engine overspeed or internal
damage.
CAUTION
ALWAYS be environmentally responsible.
Follow the guidelines of the EPA or other
governmental agencies for the proper disposal
of hazardous materials such as engine oil,
diesel fuel and engine coolant. Consul t th e local
authoriti es or reclamation facility.
NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground, or into ground water or waterways.
Failure to follow these procedures may
seriously harm the en viron ment.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 55
Change the engine oil ev er y 250 hours of operation
after the initial change at 50 hour s. Replace the
engine oil filter at the same time. See Replace
Engine Oil and Engine Oil Filt er on page 45.
Replace Air Cleaner Element
CAUTION
The maximum air int ake restriction, in terms o f
differential pressure measurement, must not
exceed 0.90 psi ( 6.23 kPa; 635 mmAq). Clean or
replace the ai r cleaner element if the air intake
restriction exceed s t he above mentioned value.
Replace the air cleaner elem ent (Figure 5-12, (2))
every 500 hours even if it is not damaged or dirty.
When replacing t he elem ent, clean the inside of the
air cleaner case (F igure 5- 12, (4)).
If the air cleaner i s equi pped with a double element,
only remove and replac e the inner element (Figure
5-13, (1)) if the engine lacks power or the dust
indicator actuates (if equipped). This is in addition
to replacing t he outer elem ent.
Replace Fuel Filter
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
When you remove any fuel system component
to perform mainten ance ( such as changing the
fuel filter) place an approved container under
the opening to catch the fuel.
NEVER use a shop rag to catch the fuel. Vapors
from the rag are flammable and explosive.
Wipe up any spills immediately.
Wear eye protection. The fuel system is under
pressure and fuel could spray out when you
remove any fuel system co mpon ent.
Failure to compl y will result in death or serious
injury.
CAUTION
For maximum engine life, Yanmar recommend s
that when shutting the engine down, you allow
the engine to idle, without load, for five minutes.
This will allow the engine components that
operate at high temperatures, such as the
turbocharger (i f equipped) and exhaust system,
to cool slightly before the engine itself i s shut
down.
CAUTION
ALWAYS be environmentally responsible.
Follow the guidelines of the EPA or other
governmental agencies for the proper disposal
of hazardous materials such as engine oil,
diesel fuel and engine coolant. Consul t th e local
authoriti es or reclamation facility.
NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground, or into ground water or waterways.
Failure to follow these procedures may
seriously harm the en viron ment.
4TNV98 & 4TNE98 (for D25G) Only
Replace the fuel filt er at specified interval s to
prevent contaminants from adversely affecting the
diesel fuel flow.
1. Stop the engine and allow it to cool.
2. Close the fuel cock of the fuel filter / water
separator.
3. Remove the fuel filt er with a fil ter wrench, turning
it to the left (Figure 5-14, (1)). When removing
the fuel filter, carefully hold it to pr ev ent t he fuel
from spilling. W ipe up all spi lled fuel.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance
56
Figure 5-14
4. Clean the filter mounting surface and apply a
small amount of diesel fuel to the gasket of the
new fuel filter.
5. Install the new fuel filt er. Turn to the right (Figure
5-14, (2)) and hand-ti ghten it only until it comes
in contact with the mounting surface. Tighten to
14-17 ft·lb (19.6-23.5 N·m; 2.0-2.4kgf·m ) or one
additional turn using the filter wrench.
Applicable Fuel Filter Part No.
4TNV98 A408064
6. Open the fuel cock of the fuel filter / water
separator.
7. Prime the fuel system. S ee Priming the Fuel
System on page 15.
8. Check for leaks.
4TNE98 (for D25S-5) On ly
Replace the fuel filt er at specified interval s to
prevent contaminants from adversely affecting the
diesel fuel flow.
1. Stop the engine and allow it to cool.
2. Close all fuel cocks i n fuel line.
3. Disconnect t he fuel fil ter sensor connector
(Figure 5-14a, (1) ) .
Figure 5-14a
4. Place an approv ed container under fuel filter.
5. Carefully open the dr ain plug (Figure 5-15a, (1))
to drain fuel from the fuel filter.
6. Remove the fuel filt er (Figu re 5- 14a, (2)) by
turning it to th e left (Figure 5-14a, (3)). Wipe up
all spilled f uel.
7. Remove the drain plug (Fig ure 5-15a, (1)) from
the fuel filter (Figu re 5- 15a, (2)) by turning it to
the left (Figure 5-15a, (3) ) .
8. Check the conditi on of t he dr ain plug O-r ing
(Figure 5-15a, (4) ) . Replace the O-ring if
damaged.
Figure 5-15
9. Set the drain plug aside for r einstal lation.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 57
10. Remove the fuel filt er sensor assembly (Figure
5-15, (5)) by turning it to the left (Figure 5-15,
(3)).
11. Carefully remove the in-line fuel filter (Figure 515, (7)) from the output nipple ( Fi gu re 5- 15, (8))
that goes to the fuel injec tion pump.
12. Dispose of the fuel, fuel fi lters and O-ring (if
replaced) properly. Follow the guidelines of the
EPA or other government agency.
13. Carefully i nstall the output nipple (Figure 5-15,
(8)).
14. Carefully i nstall the fuel filter sensor assembly
(Figure 5-15, (5) ) in the new f uel filter using the
new O-ring supplied with the fuel filter (Figure
5-15, (2)) by turning the fuel filter sensor
assembly to the right (Figure 5-15, (9)) .
15. Install the drain plug (Fi gure 5-15, (1)) on the
new fuel filter (Figure 5-15, (3)) by turning the
drain plug to the right (Figure 5- 15, (8)). Hand
tighten only.
16. Clean the fuel filter mounting surface (Fi gu re 515, (10)) and apply a small am ount of diesel fuel
to the gasket of the new filter.
17. Install the new fuel filt er (Figure 5-14, (2)) by
turning it to the right (Figu re 5- 14, (4) ) until it
contacts the mounting surfac e. Ti ghten one
additional turn.
18. Open all fuel cock s in the fuel line.
19. Reconnect the fuel fi lter sensor connector
(Figure 5-14, (1) ) .
20. Prime the fuel system . See P riming the Fuel
System on page 15.
21. Check for fuel leaks.
Applicable Fuel Filter Part No.
(Figure 5-14, (2) )
4TNE98 A409559
Clean Fuel Filter / Water Separator
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
NEVER use diesel fuel as a cleaning agent.
Failure to compl y will result in death or serious
injury.
DANGER
FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under
certain conditions.
When you remove any fuel system component
to perform mainten ance ( such as changing the
fuel filter) place an approved container under
the opening to catch the fuel.
NEVER use a shop rag to catch the fuel. Vapors
from the rag are flammable and explosive.
Wipe up any spills immediately.
Wear eye protection. The fuel system is under
pressure and fuel could spray out when you
remove any fuel system co mpon ent.
Failure to compl y will result in death or serious
injury.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance
58
CAUTION
ALWAYS be environmentally responsible.
Follow the guidelines of the EPA or other
governmental agencies for the proper disposal
of hazardous materials such as engine oil,
diesel fuel and engine coolant. Consul t th e local
authoriti es or reclamation facility.
NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground, or into ground water or waterways.
Failure to follow these procedures may
seriously harm the en viron ment.
Periodically clean the fuel filter / water separator
element and inside cup.
1. Position an approved container under the cup
(Figure5-15, (1)) of the fuel fil te r / w a te r
separator to collect the contaminants.
Figure 5-15
2. Close (Figure 5-15, ( 2)) the fuel cock ( Figure 515, (3)).
3. Loosen the drain cock (Figu re 5- 15, (4)) and
drain the contaminants. See Drain Fuel
Filter/Water Separator on page 41.
4. Turn the retaining ring (Figure 5-15, (5) ) to the
left (Figure 5-15, (10)) and remove the cup
(Figure 5-15, (6) ) . If equipped, disconnect the
sensor wi r e (Figu re 5- 15, (7)) from the cup
before removi ng the cup.
5. Carefully hol d the cup to prev ent fuel from
spilling. If you spill any fuel, clean up the spill
completely.
6. Remove the float ring (Fig ure 5-15, (8)) from the
cup. Pour the contaminants into the container
and dispose of it properly.
7. Clean the element (Figure 5-15, (9)) and inside
cup. Replace the el em ent if it is damaged.
Applicable Fuel Filter Part No.
4TNV98 A408054
4TNE98 (for D30G) A408054
8. Install the element and O- ri ng in the brac k et.
9. Position the float ring in the cup.
10. Check the conditi on of t he c up O-ri ng. Replace
if necessary.
11. Install t he cup to the brac k et by tightening the
retaining ring to the ri ght ( Fi gu re 5- 15, (6)) to a
torque of 11-15 ft·lb (15-20 N·m; 1.5-2.0kgf·m).
12. Close the drai n cock. Reconnec t the sensor
wire if equipped.
13. Open the fuel cock (Figure 5-15, (3)).
14. Prime the fuel system . See P riming the Fuel
System on page 15.
15. Check for leaks.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 59
Every 1000 Hours of Operation
Perform the following maintenance every 1000
hours of operation.
• Drain, Flush and Refill Cooling System With New
Coolant
• Adjust Intake/Exhaust Valve Clearance
Drain, Flush and Refill Cooling System With
New Coolant
DANGER
SCALD HAZARD!
NEVER remove the radiator cap if the engine is
hot. Steam and hot engine coolant will spurt out
and seriously burn you. Allow the engine to
cool down before you attempt to remove the
radiator cap.
Tighten the radiator cap securely after you
check the radiator. Steam can spurt out during
engine operation if the cap is loose.
ALWAYS check the level of the engine coolant
by observing the reserve tank.
Failure to compl y will result in death or serious
injury.
WARNING
BURN HAZARD!
Wait until the engine cools before you drain the
engine coolant . Hot engine coolant may splash
and burn y ou .
Failure to comply could result in death or
serious injury.
CAUTION
COOLANT HAZARD!
Wear eye protection and rubber gloves when
you handle long life or extended life engine
coolant. If contact with th e eyes or skin should
occur, flush eyes and wash immediately with
clean water.
Failure to comply may result in minor or
moderate injury.
CAUTION
ALWAYS be environmentally responsible.
Follow the guidelines of the EPA or other
governmental agencies for the proper disposal
of hazardous materials such as engine oil,
diesel fuel and engine coolant. Consul t th e local
authoriti es or reclamation facility.
NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground, or into ground water or waterways.
Failure to follow these procedures may
seriously harm the en viron ment.
Engine coolant contaminated with rust or scale
reduces the cooli ng eff ect. Ev en when extended life
engine coolant is properly mixed, the engine
coolant gets contaminat ed as i ts ingredients
deteriorat e. Drain, flush and refill the cooling
system with new coolant ev er y 1000 hours or once
a year, whichever comes first.
1. Allow engine and coolant to cool.
2. Remove the radiat or cap (Figure 5-16, (1)).
3. Remove the drain plug or open the drain cock
(Figure 5-16, (2) ) at t he lower port ion of the
radiator and drain the engine coolant.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance
60
Figure 5-16
4. Drain the coolant from the engine block.
• On models not equipped with an oil cooler,
remove the coolant dr ain plug (Figure 5-17,
(1)) from the engine block.
Figure 5-17
5. After draining the engine coolant, flush the
radiator and engine block to remove any rust,
scale and contaminants. Then rei nstall and
tighten the drain plug or close the drain cock in
the radiator. Reinstall and tighten the cylinder
block drain plug or rec onnec t the coolant hose at
the oil cooler.
6. Fill radiator and engine with engine coolant. See
Filling Radiator with Engine Coolant on page 19.
Adjust Intake / Exhaust Valve Clearance
Proper adjustment is necessary to maintain the
correct timi ng for opening and closing the valves.
Improper adjustm ent will cause the engine to run
noisily, resulting in poor engine perform anc e and
engine damage. See I ntake/Ex haust Valve and
Guide on page 67.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 61
Every 1500 Hours of Operation
Perform the following maintenance every 1500
hours of operation.
• Inspect, Clean and Test F uel Injectors
• Inspect Crankcase Breather System
Inspect, Clean and Test Fuel Injectors
WARNING
HIGH-PRESSURE HAZARD!
Avoid skin contact with the high-pressure
diesel fuel spray caused by a fuel system leak
such as a broken fuel injection line. Highpressure fuel can penetrat e your skin and result
in serious injury. If you are exposed to highpressure fuel spray, obtain prompt medical
treatment.
NEVER check for a fuel leak with your hands.
ALWAYS use a piece of wood or cardboard.
Have your authorized Yanmar industri al engine
dealer or distributor repair the damage.
Failure to comply could result in death or
serious injury.
Proper operati on of t he fuel injectors is required to
obtain the optimum injec tion pattern for full engine
performanc e. The EPA / ARB requires that the fuel
injectors are i nspect ed, cleaned and tested every
1500 hours. See Testing of F uel Injectors on page
164.
This procedure i s considered normal maintenance
and is performed at the owner’s expense. This
procedure is not cover ed by the Yanmar Limited
Warranty.
Inspect Crankcase Breath er S ystem
Proper operati on of t he crankc ase breather system
is required to mai ntain the emission requirements of
the engine. The EPA / ARB requires that the
crankcase breather system is inspected every 1500
hours.
There are three different crankcase breather
systems used on the TNV engines. Only the nonturbo TNV engines crankcase breather system
requires periodic maintenance.
The non-turbo TNV engines use a crankcase
breather system t hat has a spring- bac k ed
diaphragm (Fi gure 5-19, (1)) in the valve cover
(Figure 5-19, (2) ) . When the crankcase pressure
reaches a predetermined value, the diaphragm
opens a passage that allows crankcase fumes to be
routed to the intake manifold.
To inspect the diaphr agm and spring (Figure 5-19,
(3)):
1. Remove the bolts retaining the diaphr agm c ov er
(Figure 5-19, (4) ) .
Figure 5-19
2. Remove the diaphragm c ov er, spring, diaphragm
plate (Figure 5-19, (5)) and diaphragm.
3. Inspect the diaphragm for tears. Inspect the
spring for distor tion. Replace components if
necessary.
4. Reinstall the diaphragm , diaphragm plate, spring
and diaphragm cover. Tighten the diaphragm
bolts to specified tor que.
4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance
62
Failure of the diaphragm and / or spring will cause
the loss of pressure control and allow an excessive
amount of crankc ase fum es to be rout ed to the
intake manifold. This could result in excessive
deposits in the intake system, high engine exhaust
smoke levels, exc essive engine oil consumption,
and / or engine run-on due to the burning of the
engine oil.
Every 2000 Hours of Operation
Perform the following maintenance every 2000
hours of operation.
• Check and Replace Fuel Hoses and Engine
Coolant Hoses
• Lap the Intake and Exhaust Valves
Check and Replace Fuel Hoses an d Engine
Coolant Hoses
CAUTION
ALWAYS be environmentally responsible.
Follow the guidelines of the EPA or other
governmental agencies for the proper disposal
of hazardous materials such as engine oil,
diesel fuel and engine coolant. Consul t th e local
authoriti es or reclamation facility.
NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground, or into ground water or waterways.
Failure to follow these procedures may
seriously harm the en viron ment.
Regularly check the fuel system and engine coolant
system hoses. If they are cracked or degraded,
replace them. Replace the hoses at least every two
years.
Lap the Intake and Exhaust Valves
Adjustment is necessary t o maintain proper contact
of the valves and seats. See Inspection of Intake
and Exhaust Valves on page 98.
Section 3. Engine 63
Section 3. ENGINE
Before You Begin Servicing
WARNING
To prevent possible eye injury, always wear
SAFETY GLASSES while servicing the engine.
WARNING
ENTANGLEMENT HAZARD!
Stop the engine before you begin to service it.
NEVER leave the key in the key switch when you
are servicing the engine. Someone may
accidentally st art the engine and not real ize you
are servicing it. This could result in a serious
injury.
If you must service the engine while it is
operating, remo ve all jewelry, tie back long h air,
and keep your hands, other body parts and
clothing away from moving/rotating parts.
Failure to comply could result in death or
serious injury..
WARNING
FUME / BURN HAZARD!
Always read and follow safety related
precautions found on containers of hazardous
substances like parts cleaners, pri mers, sealants
and sealant removers.
Failure to comply could result in death or
serious injury.
CAUTION
FLYING OBJECT HAZARD!
ALWAYS wear eye protect ion when servicing the
engine and when using compressed air or highpressure water. Dust , flying debris, compressed
air, pressurized water or steam may injure your
eyes.
Failure to comply may result in minor or
moderate injury.
CAUTION
Be sure to secure the engine solidly to prevent
injury or damage to parts due to the engine
falling during work on the engine.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 64
CAUTION
Only use the engine oil specified. Other engine
oils may affect warranty coverage, cause
internal engine components to seize and / or
shorten engine life.
Prevent dirt and debris from contaminating the
engine oil. Carefully clean the oil cap/dipstick
and the surrounding area before you remove the
cap.
NEVER mix different types of engine oil. This
may adversely affect the lubricating properties
of the engine oil.
NEVER overfill. Overfilling may result in white
exhaust smoke, engine overspeed or internal
damage.
CAUTION
Only use the engine coolant specified. Other
engine coolants may affect warranty coverage,
cause an internal buildup of rust and scale
and/or shorten engine life.
Prevent dirt and debris from contaminating the
engine coolant. Carefully clean the radiator cap
and the surrounding area before you remove the
cap.
NEVER mix different types of engine coolants.
This may adversely affect the properties of the
engine coolant.
CAUTION
Identify all parts and their location using an
appropriate meth od. It is important th at all parts
are returned to the same position during the
reassembly process.
CAUTION
Any part which i s found defective as a result of
inspection or any part whose measured value
does not satisfy the standard or limit must be
replaced.
CAUTION
Any part determined to not meet the service
standard or limit before the next service, as
determined from the state of current rate of wear,
should be replaced even though the part
currently meets the service standard limit.
CAUTION
Remove or install the high-pressure fuel
injection lines as an assembly whenever
possible. Disassembling the high-pressure fuel
injection lines from the retainers or bending any
of the fuel lin es will make it difficult to reinstall
the fuel lines.
CAUTION
Do not loosen or remove the four bolts retaining
the fuel injection pump drive gear to the fuel
injection pump hub. Do not disassemble the fuel
injection pump drive gear from the hub. Correct
fuel injection timing will be very difficult or
impossible to achieve.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 65
CAUTION
Keep the piston pin parts, piston assemblies,
and connecting rod assemblies together to be
returned to the same position during the
reassembly process. Label the parts using an
appropriate meth od .
CAUTION
Do not allow the honing tool to operate in one
position for any length of time. Damage to the
cylinder wall will occur. Keep the tool in
const a nt up-and-down mo tion.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 66
Introduction
This section of the Servic e M anual descr ibes
servicing of the engine.
Cylinder Head Specifications
Adjustment Specifications
Model Valve Clearance
Valve Bridge Clearance
(4-Valve Head Only)
4TNV98
0.006 - 0.010 in.
(0.15 - 0.25 mm)
0
4TNE98
0.006 - 0.010 in.
(0.15 - 0.25 mm)
-
Cylinder Head
4TNV98 Engine
Inspection Item Standard Limit
Reference
Page
Combustion Surfac e Distor tion (Flatness)
0.0020 in.
(0.05 mm) or less
0.0059 in.
(0.15 mm)
Valve Recession
4TNV98
(4-Valve Head)
Intake
Exhaust
0.0142 - 0.0220 in.
(0.36 - 0.56 mm)
0.0138 - 0.0217 in.
(0.35 - 0.55 mm)
0.0315 in.
(0.8 mm)
0.0315 in.
(0.8 mm)
See Valve
Recession
on
Page 95
and 98.
Intake 120° -
Seat Angle
Exhaust 90° -
Valve Seat
(4-Valve)
Seat Correction Angle 40°, 150° -
See Valve
Face and
Valve Seat
on
Page 96
and 99.
4TNE98 Engine
Inspection Item Standard Limit
Reference
Page
Combustion Surfac e Distor tion (Flatness)
0.0020 in.
(0.05 mm) or less
0.0059 in.
(0.15 mm)
See
Inspection
of Cylinder
Head on
page 94.
Intake
0.020 - 0.028 in.
(0.5 - 0.7 mm)
0.039 in.
(1.0 mm)
Valve Sink
Exhaust
0.024 - 0.032 in.
(0.6 - 0.8 mm)
0.043 in.
(1.1 mm)
Intake 120° -
Valve Seat Angle
Exhaust 90° -
See
Inspection
of Intake
and
Exhaust
Valves on
page 95.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 67
Intake / Exhaust Valve and Guide Cont
4TNV98 Engine
Inspection Item Standard Limit
Reference
Page
Gui de Ins ide Diam eter
0.2756 - 0.2762 in.
(7.000 - 7.015 mm)
0.2787 in.
(7.08 mm)
Valve Stem Outsi de
Diameter
0.2734 - 0.2740 in.
(6.945 - 6.960 mm)
0.2717 in.
(6.90 mm)
Intake
Oil Clea ranc e
0.0016 - 0.0028 in.
(0.040 - 0.070 mm)
0.0067 in.
(0.17 mm)
Gui de Ins ide Diam eter
0.2756 - 0.2762 in.
(7.000 - 7.015 mm)
0.2787 in.
(7.08 mm)
Valve Stem Outsi de
Diameter
0.2732 - 0.2738 in.
(6.940 - 6.955 mm)
0.2717 in.
(6.90 mm)
4TNV98
(4-Valve Head)
Exhaust
Valve Stem Bend
0.0018 - 0.0030 in.
(0.045 - 0.075 mm)
0.0067 in.
(0.17 mm)
See
Inspection of
Valve
Guides on
page 94.
Valve Guide Projection From Cylinder Head
0.3819 - 0.3937 in.
(9.70 - 1 0 .0 0 mm)
-
See
Reassembly
of Valve
Guides on
page 97
and 103.
Valve Guide Installation Method Cold-fitted -
Valve Stem Seal Projection From Cylinder Head
0.460 - 0.472 in.
(11.7 - 12.0 mm)
-
See
Reassembly
of Intake and
Exhaust
Va lves on
page 98.
4TNE98 Engine
Inspection Item Standard Limit
Reference
Page
Gui de Ins ide Diam eter
0.3156 - 0.3161 in.
(8.015 – 8.030 mm)
0.3189 in.
(8.10 mm)
Valve Stem Outsi de Di ameter
0.3136 - 0.3142 in.
(7.965 – 7.980 mm)
0.3110 in.
(7.90 mm)
Intake Valve
Oil Clea ranc e
0.0014 - 0.0026 in.
(0.035 - 0.065 mm)
0.0071 in.
(0.18 mm)
Gui de Ins ide Diam eter
0.3156 - 0.3161 in.
(8.015 – 8.030 mm)
0.3189 in.
(8.10 mm)
Valve Stem Outsi de Di ameter
0.3136 - 0.3138 in.
(7.965 – 7.970 mm)
0.3110 in.
(7.90 mm)
Exhaust Valve
Oil Clea ranc e
0.0018 - 0.0030 in.
(0.045 - 0.075 mm)
0.0071 in.
(0.18 mm)
See
Inspection of
Intake and
Exhaust
Va lves on
page 95.
Valve Guide Projection From Cylinder Head
0.58 - 0.60 in.
(14.7 – 15.0 mm)
-
See
Assembly of
Valve
Guides on
page 98.
Valve Stem Seal Projection From Cylinder Head
0.66 - 0.70 in.
(16.7 – 17.0 mm)
-
See
Assembly of
Valve
Guides on
page 98.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 68
Push Rod
Inspection Item St andard Limit
Reference
Page
Page Push Rod Bend
Less than
0.0012 in. (0.03 mm)
0.0012 in.
(0.03 mm)
See Push
Rod Bend
on page 93.
Rocker Arm and Shaft
Inspection Item St andard Limit
Reference
Page
Arm Sh aft H ole Diameter
0.7283 - 0.7291 in.
(18.500 - 18.520 mm)
0.7311 in.
(18.57 mm)
Shaft Outside Diameter
0.7272 - 0.7280 in.
(18.470 - 18.490 mm)
0.7260 in.
(18.44 mm)
Oil Clearance
0.0004 - 0.0020 in.
(0.010 - 0.050 mm)
0.0051 in.
(0.13 mm)
See
Inspection of
Rocker Arm
Assembly on
page 93 and
94.
Valve Spring
Inspect ion Item Model Sta nda r d Limit
Reference
Page
4TNV98 (4-Valve Head)
1.5630 in.
(39.7 mm)
1.5433 in.
(39.2 mm)
Free Length
4TNE98
1.87 in.
(47.5 mm)
-
4TNV98 (4-Valve Head) -
0.0551 in.
(1.4 mm)
Squareness
4TNE98 -
0.05 in.
(1.2 mm)
See
Inspection of
Valve
Springs on
page 97 and
101.
Camshaft and Timing Gear Train Specifications
Camshaft
Inspection Item St andard Limit
Reference
Page
End Play
0.0020 - 0.0079 in.
(0.05 - 0.20 mm)
0.0118 in.
(0.030 mm)
See
Removal of
Camshaft on
page 114.
Bend (1/2 the dial gauge reading)
0 - 0.0008 in.
(0 - 0.02 mm)
0.0020 in.
(0.05 mm)
4TNV98
1.7087 - 1.7165 in.
(43.400 - 43.600 mm)
1.6988 in.
(43.150 mm)
Cam Lobe Height
4TNE98
1.6707 - 1.6758 in.
(42.435– 42.565 mm)
1.6608 in.
(42.185 mm)
See
Inspection of
Camshaft on
page 125.
Shaft Outside Diameter / Beari ng Inside Diameter
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 69
(Camshaft Cont.)
Inspection Item St andard Limit
Reference
Page
Bushing Inside Diam eter
1.9681 - 1.9707 in.
(49.990 - 50.055 mm)
1.9736 in.
(50.130 mm)
Camshaft Outside Diamet er
1.9655 - 1.9665 in.
(49.925 - 49.950 mm)
1.9642 in.
(49.890 mm)
Gear End
Oil Clearance
0.0016 - 0.0051 in.
(0.040 - 0.130 mm)
0.0094 in.
(0.240 mm)
Bushing Inside Diam eter
1.9685 - 1.9695 in.
(50.000 - 50.025 mm)
1.9724 in.
(50.100 mm)
Camshaft Outside Diamet er
1.9650 - 1.9659 in.
(49.910 - 49.935 mm)
1.9636 in.
(49.875 mm)
Intermediate
Oil Clearance
0.0026 - 0.0045 in.
(0.065 - 0.115 mm)
0.0089 in.
(0.225 mm)
Bushing Inside Diam eter
1.9685 - 1.9695 in.
(50.000 - 50.025 mm)
1.9724 in.
(50.100 mm)
Camshaft Outside Diamet er
1.9655 - 1.9665 in.
(49.925 - 49.950 mm)
1.9642 in.
(49.890 mm)
Flywheel End
Oil Clearance
0.0020 - 0.0039 in.
(0.050 - 0.100 mm)
0.0083 in.
(0.210 mm)
See
Inspection of
Camshaft on
page 125.
Idler Gear Shaft and Bushing
Inspection Item S t andard Limit
Reference
Page
Shaft Outside Diameter
1.8091 - 1.8100 in.
(45.950 - 45.975 mm)
1.8071 in.
(45.900 mm)
Bushing Inside Diam eter
1.8110 - 4.8120 in.
(46.000 - 46.025 mm)
1.8140 in.
(46.075 mm)
Oil Clearance
0.0010 - 0.0030 in.
(0.025 - 0.075 mm)
0.0069 in.
(0.175 mm)
See
Inspection of
Idler Gear
and Shaft on
page 126.
Timing Gear Backlash
Inspection Item S t andard Limit
Reference
Page
Crank Gear, Cam Gear, Idler Gear, Fuel Injection
Pump Gear and PTO Gear
0.0031 - 0.0055 in.
(0.08 - 0.14 mm)
0.0063 in.
(0.16 mm)
Lubricating Oil P um p Gear
0.0035 - 0.0059 in.
(0.09 - 0.15 mm)
0.0067 in.
(0.17 mm)
See
Checking
Timing Gear
Backlash on
page 112.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 70
Crankshaft and Piston Specifications
Crankshaft
NOTE : Check appropriate parts catalog for various
sizes of replacement main bearing inserts.
Inspection Item S t andard Limit
Reference
Page
Bend (1/2 the dial gauge reading) -
0.0008 in.
(0.02 mm)
Journal Outside
Diameter
2.2816 - 2.2820 in.
(57.952 - 57.962 mm)
2.2796 in.
(57.902 mm)
Bearing Inside
Diameter
2.2835 - 2.2845 in.
(58.000 - 58.026 mm)
-
Bearing Insert
Thickness
0.0587 - 0.0591 in.
(1.492 - 1.500 mm)
-
Connecting Rod Journals
Oil Clearance
0.0015 - 0.0029 in.
(0.038 - 0.074 mm)
0.0059 in.
(0.150 mm)
See
Inspection of
Crankshaft
on Page
124.
Journal Outside
Diameter
2.5572 - 2.5576 in.
(64.952 - 64.962 mm)
2.5552 in.
(64.902 mm)
Bearing Inside
Diameter
2.5590 - 2.5598 in.
(65.000 - 65.020 mm)
-
Bearing Insert
Thickness
0.0785 - 0.0791 in.
(1.995 - 2.010 mm)
-
Main Bearing Journal
Oil Clearance
0.0015 - 0.0027 in.
(0.038 - 0.068 mm)
0.0059 in.
(0.150 mm)
See
Inspection of
Crankshaft
on page
124.
Thrust Bearing
Inspection Item S t andard Limit
Reference
Page
4TNV98
0.0051 - 0.0091 in.
(0.13 - 0.23 mm)
0.0110 in.
(0.28 mm)
Crankshaft End Play
4TNE98
0.0043 - 0.0083 in.
(0.11 - 0.21 mm)
0.0110 in.
(0.28 mm)
See
Removal of
Crankshaft
on Page
1 18.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 71
Piston
Inspection Item Standard Limit
Reference
Page
Piston Outside Diamet er
(Measure at 90° to the Piston Pin.)
3.8555 - 3.8567 in.
(97.930 - 97.960 mm)
3.8541 in.
(97.895 mm)
Piston Diameter Measure Location(Upward
From the Bottom of the Piston.)
0.8661 in.
(22 mm)
-
See
Inspection of
Pistons,
Piston Rings
and Wrist
Pin on page
122.
Hole Inside Diamet er
1.1811 - 1.1815 in.
(30.000 - 30.009 mm)
1.1826 in.
(30.039 mm)
Pin Outside Diameter
1.1807 - 1.1811 in.
(29.989 - 30.000 mm)
1.1795 in.
(29.959 mm)
Piston Pin
Oil Clearance
0.0000 - 0.0008 in.
(0.000 - 0.020 mm)
0.0031 in.
(0.080 mm)
See
Inspection of
Pistons,
Piston Rings
and Wrist
Pin on page
122.
Piston Ring
Model Inspection Item Standard Limit
Reference
Page
Ring Groove Wi dth
0.0803 - 0.0811 in.
(2.040 - 2.060 mm)
-
Ring Width
0.0764 - 0.0772 in.
(1.940 - 1.960 mm)
0.0756 in.
(1.920 mm)
Side Clearance
0.0031 - 0.0047 in.
(0.080 - 0.120 mm)
-
Top Ring
End Gap
0.0098 - 0.0177 in.
(0.250 - 0.450 mm)
0.0213 in.
(0.540 mm)
Ring Groove Wi dth
0.0819 - 0.0825 in.
(2.080 - 2.095 mm)
0.0864 in.
(2.195 mm)
Ring Width
0.0776 - 0.0783 in.
(1.970 - 1.990 mm)
0.0768 in.
(1.950 mm)
Side Clearance
0.0035 - 0.0049 in.
(0.090 - 0.125 mm)
0.0096 in.
(0.245 mm)
Second Ring
End Gap
0.0177 - 0.0256 in.
(0.450 - 0.650 mm)
0.0287 in.
(0.730 mm)
Ring Groove Wi dth
0.1187 - 0.1193 in.
(3.015 - 3.030 mm)
0.1232 in.
(3.130 mm)
Ring Width
0.1169 - 0.1177 in.
(2.970 - 2.990 mm)
0.1161 in.
(2.950 mm)
Side Clearance
0.0010 - 0.0024 in.
(0.025 - 0.060 mm)
0.0071 in.
(0.180 mm)
4TNV98
Oil Ring
End Gap
0.0098 - 0.0177 in.
(0.250 - 0.450 mm)
0.0217 in.
(0.550 mm)
See
Inspection of
Pistons,
Piston Rings
and Wrist
Pin on page
122.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 72
Connecting Rod
Connecting Rod Small End
Inspection Item Standard Limit Reference Page
Wrist Pin Bushing Inside Di am eter
1.1821 - 1.1826 in.
(30.025 - 30.038 mm)
1.1838 in.
(30.068 mm)
Wrist Pin Outside Diameter
1.1806 - 1.1811 in.
(29.987 - 30.000 mm)
1.1795 in.
(29.959 mm)
Oil Clearance
0.0010 - 0.0020 in.
(0.025 - 0.51 mm)
0.0043 in.
(0.109 mm)
See Inspection of
Connecting Rod on
page 124.
Connecting Rod Big End
Inspection Item Standard Limit
Reference
Page
4TNV98
0.0079 - 0.0157 in.
(0.20 - 0.40 mm)
Side Clearance
(Thrust Clearanc e)
4TNE98 0.0051 - 0.0091 in. -
See Inspection of
Connecting Rod on
page 124.
See Special Torque Chart on page 69 for other specifications.
Tappet
Inspection Item Standard Limit Reference Page
Tappet Bore (Bloc k ) I nsi de Diameter
0.4724 - 0.4731 in.
(12.000 - 12.018 mm)
0.4739 in.
(12.038 mm)
Tappet Stem Outside Diameter
0.4715 - 0.4720 in.
(11.975 - 11.990 mm)
0.4707 in.
(11.955 mm)
Oil Clearance
0.0004 - 0.0017 in.
(0.010 - 0.043 mm)
0.0033 in.
(0.083 mm)
See Inspection of
Tappets on page
124.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 73
Cylinder Block Specifications
Cylinder Block
Inspection Item Standard Limit
Reference
Page
Cylinder Inside Diam eter
3.8583 - 3.8594 in.
(98.000 - 98.030 mm)
3.8634 in.
(98.130 mm)
Roundness
Cylinder Bore
Taper
0.0004 in. (0.01 mm)
or less
0.0012 in.
(0.03 mm)
See
Inspection
of Cylinder
Block on
page 121.
Special Torqu e Chart
Torque for Bolts and Nuts
Component
Thread Diameter
and Pitc h
Torque
Lubricating Oil
Application
(Thread Portion
and Seat Surface)
Cylinder Head Bolt M11 x 1.25 mm
76 - 83 ft·lb
(103.1 - 112.9 N·m;
10.5 - 11.5 kgf·m)
Applied
Connecting Rod Bolt M10 x 1. 0 mm
40 - 43 ft·lb
(53.9 - 58.8 N·m;
5.5 - 6.0 kgf·m)
Applied
Flywheel Bolt M14 x 1.5 mm
137 - 152 ft·lb
(186.2 - 205.8 N·m;
19 - 21 kgf·m)
Applied
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 74
(Torque for Bolts and Nuts Cont.)
Component
Thread Diameter and
Pitch
Torque
Lubricating Oil
Application
(Thread Portion
and Seat Surface)
Main Bearing Cap Bolt M11 x 1.25 mm
80 - 87 ft·lb
(108.1 - 117.9 N·m;
11.0 - 12.0 kgf·m)
Applied
Crankshaft Pulley Bolt M14 x 1.5 mm
80 - 94 ft·lb
(107.9 - 127.5 N·m;
11.0 - 13.0 kgf·m)
Applied
Fuel Injector
Bolt
4TNV98 M8 x 1.25 mm
17 - 21 ft·lb
(22.6 - 28.4 N·m;
2.3 - 2.9 kgf·m)
Not Applied
Fuel Pump
Drive Gear
Nut
4TNV98 M18 x 1.5 mm
83 - 90 ft·lb
(113 - 123 N·m;
11.5 - 12.5 kgf·m)
Not Applied
High-Pressure
Fuel Lines Bolt
4TNV98 M12 x 1.5 mm
174 - 217 in·lb
(19.6 - 24.5 N·m;
2.0 - 2.5 kgf·m)
Not Applied
Fuel Return
Line Joint Bolt
4TNV98 M6 x 1.0 mm
70 - 86 in·lb
(7.8 - 9.8 N·m;
0.8 - 1.0 kgf·m)
Not Applied
See Tightening Torques for Standard Bolts and Nuts on page 23 for standard hardware torque values.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 75
Special Service Tools
No. Tool Name Applicable Model and Tool Size Illustration
Model L1 L2 d1 d2
4TNV98
0.787 in.
(20 mm)
2.953 in.
(75 mm)
0.256 in.
(6.5 mm)
0.394 in.
(10 mm)
4TNE98
0.787 in.
(20 mm)
2.953 in.
(75 mm)
0.295 in.
(7.5 mm)
0.433 in.
(1 1 mm)
1
Valve Guide
Tool (For
Removing
Valve Guide)
Locally Manufac tured
Model L1 L2 d1 d2
4TNV98
0.276 in.
(7 mm)
2.362 in.
(60 mm)
0.512 in.
(13 mm)
0.630 in.
(16 mm)
4TNE98
0.591 in.
(15 mm)
2.559 in.
(65 mm)
0.551 in.
(14 mm)
0.787 in.
(20 mm)
2
Valve Guide
Tool (For
Installing
Valve Guide)
Locally Manufac tured
L1 L2 d1 d2
0.787 in.
(20 mm)
3.937 in.
(100 mm)
1.181 in.
(30 mm)
1.299 in.
(33 mm)
4
Connecting
Rod Bushing
Replacer
(For
Removal/
Installation of
Connecting
Rod
Bushing)
Locally Manufac tured
5
Valve S pring
Compressor
(For
Removal/
Installation of
Valve S pring)
Yanmar Part No.
129100-92630
Model d1 d2 d3 L1 L2 L3
4TNV98
0.598
in.
(15.2
mm)
0.827
in.
(21
mm)
0.472
in.
(12
mm)
0.465
in.
(11.8
mm)
2.559
in.
(65
mm)
0.157
in.
(4
mm)
4TNE98
0.638
in.
(16.2
mm)
0.866
in.
(22
mm)
0.531
in.
(13.5
mm)
0.669
in.
(17.0
mm)
2.560
in.
(65
mm)
0.157
in.
(4
mm)
6
Stem Seal
Installer
(for Installi ng
Valve Stem
Seal)
Locally Manufac tured
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 76
(Special Service Tools Cont.)
No. Tool Name Applicable Model and Tool Size Illustration
7
Filter Wrench
(For Removal
/ Installation
of Engine Oil
Filter)
Available Locally
L1 L2 d1 d2
0.709 in.
(18 mm)
2.756 in.
(70 mm)
1.968 in.
(50 mm)
2.087 in.
(553 mm)
Allowance
: d1
, d2
8
Camshaft
Bushing T ool
(For
Extracting
Camshaft
Bushing)
Locally Manufac tured
Yanmar Part No. Cylinder Bor e
9
Flex-Hone
(For
Preparation
of Cylinder
Walls)
129400-92440
3.504 - 3.976 in.
(89 - 101 mm)
10
Piston Ring
Compressor
(For Installing
Piston)
Yanmar Part No. 95550-002476
The Piston Inserti on Tool is Applicable for 2.362 - 4.921 in.
(60 - 125 mm) Diameter Pistons
11
Piston Ring
Expander
(For Removal
/ Installation
of Piston
Ring)
Available Locally
12
Crankshaft
Pulley
Installing Tool
Locally Manufac tured
- 0.3
- 0.6
- 0.3
- 0.6
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 77
Measuring Instruments
No. Instrument Name Application Illustration
1 Dial Indicator Locally Available Measure shaft bend and end play
2 Test Indicator Locally Available
Measurements of narr ow or deep
portions that c annot be measured by dial
gauge
3 Magnetic Stand Locally Available
For holding the dial gauge when
measuring
4 Micrometer Locally Available
For measuring the outsi de diam eters of
crankshaft, pistons, piston pins, etc.
5
Cylinder Bore
Gauge
Loca lly Availab le
For measuring the insi de diameters of
cylinder li ner s, beari ng bores, etc.
6 Calipers Locally Available
For measuring outside diameters, depth,
thickness and width
7
Depth
Micrometer
Locally Available For measuring of valve recession
8 Square Locally Available
For measuring valve spring inclination
and straightness of parts
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 78
No. Instrument Name Application Illustration
9 V-Block Locally Available For measuring shaft bend
10 Torque Wrench Locally Available
For tightening nuts and bolts to t he
specified t or que
11 Feeler Gauge Locally Available
For measuring pi ston ring gaps,
piston ring clear anc e, and valve
adjustment clearanc e
12 Battery Coolant Tester
For checking concentration of
antifreez e and the bat tery electrolyte
charge status
13 Digital Thermometer For measuring temperatures
Contact Type
For measuring revolution by
contacting the revolving shaft
Photoelectric
Type
For measuring revolution by sensing
the reflecting m ar k on the outer
periphery of the rev olv ing shaft
14 Tachometer
Fuel High
Pressure Pipe
Clamp Type
This measures the rev olution
regardless of the c enter or periphery
of the revolving object
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 79
No. Instrument Name Application Illustration
15 Circuit Tester
For measuring resistance, voltage and
continuity of electrical circuits
Compression Gauge Kit
For measuring compression
pressureGauge Set Part No. TOL97190080
16
New Comperssion Test
Adaptor
Adapter for direct injection 2-valve
cylinder headAdapt er P ar t No. 11980292950
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 80
Cylinder Head
Cylinder Head Components
4TNV98 Engine
Figure 6-36
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 81
(1) Crankcase Breather Cover. (2) Diaphragm Spring. (3) Diaphragm Cup.
(4) Crankcase Breather Diaphragm. (5) Oil Fill Cap. (6) Valve Cover Nut.
(7) Valve Cover Nut O-Ring . (8) Valve Cover Gasket. (9) Support Bolt.
(10) Rocker Arm Shaft Support. (11) Wave Washer. (12) Fuel Injector Ret ai n er B olt.
(13) Valve Adjusting Screw (Primary). (14) Valve Adjusting Screw Lock Nut (Primary).
(15) Rocker Arm Shaft Aligning Stud. (16) Fuel Inj ect or Ret ai n er. (17) Valve Stem Seal.
(18) Valve Guide. (19) Cylinder Head. (20) Intake Valve.
(21) Exhaust Valve. (22) Cylinder Head Gasket. (23) Fu el In j ector Nozzl e Pr ot ec tor.
(24) Fuel Inj ector Nozzl e Seat. (25) Valve Spring. (26) Valve Bridge Guide.
(27) Spring Retainer. (28) Valve Keepers. (29) Valve Bridge.
(30) Valve Bridge Seat. (31) Valve Adjusting Screw Lock Nut (Secondary). (32) Valve Adjusting Screw (Secondary).
(33) Push Rod. (34) Rocker Arm Shaft. (35) Crankcase Breather Components.
(36) Valve Cover.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 82
Disassembly of 4-Valve Cylinder Head
Prepare a clean, flat worki ng surf ac e on a
workbench large enough to accom modate the
cylinder head assembl y. Discard all gaskets, O-rings
and seals. Use new gaskets, O-rings and seals on
reassembly of the cylinder head.
1. Drain the coolant from the engine into a suitable
container. See Drain, Flush and Refill Cooli ng
System with New Coolant on page 163.
CAUTION
Identify all parts and their location using an
appropriate meth od. It is important th at all parts
are returned to the same position during the
reassembly process.
2. Remove the high pressure f uel injection lines
(Figure 6-37, (1) ) . See Rem ov al of F uel Injectors
on page7-31.
Figure 6-37
CAUTION
Remove or install the high-pressure fuel
injection lines as an assembly whenever
possible. Disassembling the high-pressure fuel
injection lines from the retainers or bending any
of the fuel lin es will make it difficult to reinstall
the fuel lines.
3. Disconnect t he fuel return hose (Figure 6-37, (2) )
from the cylinder head.
4. Disconnect t he hoses (Fi gure 6-37, (3)) from the
cold start device on the fuel injection pump.
5. Remove the turbocharger - to-intake manifold hose
(Figure 6-38, (1) ) (if equipped).
6. Disconnect t he electr ic al wir e from the intake air
heater (Figu re 6- 38, (12)).
7. Remove the intake manifold bolts (Figure 6-38,
(11)). Remove the intake manifold ( Fi gu re 6- 38,
(10)). Discard the intake manifold gasket (Figure
6-38, (9)).
8. Remove the exhaust manifold bolts (Figure 6-38,
(7)). Remove the exhaust manif old (F igure 6- 38,
(6)) with the turbocharger attached. Discard the
exhaust manifold gasket. (Figure 6-38, (5)).
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 83
Figure 6-38
10. Remove the engine coolant pump. See
Disassembly of Engine Coolant Pump on page
207.
Removal of Valve Cover
NOTE: The high pressure fuel inj ection lines and
valve cover grommets must be remov ed prior to
removing the valve cover. See Removal of Fuel
Injector s on page 163.
1. Remove the high-pressure fuel lines.
2. Use a flat-blade screwdriver (Figure 6-39) to
remove the fuel injection line grommets (Figure 640, (1)) from the valve cover (Figu re 6- 40, (3))
and fuel injector s (Fi gu re 6- 40, (2)). There is a
notch at the 3 o’clock position in the valve cover
opening to insert the screwdriver.
Figure 6-39
3. Remove the valve cover nuts (Figure 6- 40, (4)).
4. Remove the O-ring (Figure 6-40, (5)) on each
valve cover nut.
Figure 6-40
5. Remove the valve cover (Fig ure 6-40, (3)).
Discard the valve cover gasket (Figure 6-40, (6)) .
6. Inspect and clean the c r ank c ase breat her
assembly. See Inspect Crankcase Breather
System on page 61.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 84
Removal of Rocker Arm Assembly
1. Remove the fuel injec tors from the cylinder head.
See Removal of Fuel Inj ector s on page 163.
2. Remove the bolts (Figure 6-41, ( 1)) that retain the
rocker arm shaft supports to the cylinder head.
3. Remove the rocker arm and shaft assem bly from
the cylinder head.
NOTE : Identify the push rods and valve bridges so
they can be installed in thei r original locations.
4. Remove the push rods (Figure 6-41, (2)).
5. Remove the valve bri dge assemblies (Figure 641, (3)). Remove the seat (Figure 6-41, (4)) from
each valve bridge.
6. Identify all parts so that they will be r einstalled in
their original locations.
Figure 6-41
Disassembly of Rocker Arm Assembly
NOTE : Identify the roc k er arms so they can be
reinstalled wit h the original matching valve and
pushrod.
1. Remove the rocker arm shaft alignm ent studs
(Figure 6-42, (5) ) from the roc k er arm shaft
supports (Fig ure 6-42, (6)).
2. Slide the supports, wave washers (Figure 6-42,
(7)), rocker arms (Figu re 6- 42, (8)), and fuel
injector retainers (Figure 6-42, (4) ) off the rocker
shaft (Figure 6-42, (1)), leaving these parts in
order on the bench surf ac e.
Figure 6-42
NOTE : Figure 6 -42 shows components for one
cylinder. Components for all remaining cylinders are
assembled in the same order.
3. Remove the valve adjusting screw (Figure 6-42,
(2)) and the lock nut (Figure 6-42, (3)) from the
rocker arms.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 85
Removal of Cylinder Head
1. Loosen the cylinder head bolts following the
sequence shown in (Figure 6-43).
Figure 6-43
1) Cooling Fan End
2) Camshaft Side
2. Remove the cylinder head bol ts (Figure 6-44, (1)).
3. Lift the cylinder head away from the cylinder block.
Discard the cylinder head gasket (Figure 6-44,
(2)). Place the cylinder head on the work bench t o
prevent damage to t he combustion surface.
Figure 6-44
Removal of Intake and Exhaust Valves
1. Place the cylinder head on the work bench wit h
the combustion side down.
2. Using the valve spri ng c om pr essor tool, compress
one of the valve springs (Figure 6-45).
Figure 6-45
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 86
3. Remove the valve keepers (Fig ure 6-46, (1)).
4. Slowly release the tension on the valve spring.
5. Remove the spring retainer (F ig ure 6-46, (2)),
valve spring (Figure 6-46, (3)).
Figure 6-46
6. Repeat the procedur e with all the remaining
valves.
NOTE : If the valves are to be reused, identify them
so they can be installed in their ori ginal location.
7. Remove the inject or nozzle protectors (Figure 646, (6)) and the seats (Figure 6-46, (7)).
8. Turn the cylinder head so the exhaust port side
faces down. Remove the intake and exhaust
valves (Figure 6-46, (5)) from the cylinder head.
9. Remove the valve stem seals (Fig ure 6-46, (4)).
Removal of Valve Guides
NOTE : Removal of the valve guides should be
postponed until inspect ion and measurement
procedures have been performed. See Inspection of
Valve Guides on page 94.
1. Using a drift pin and hammer, drive the valve
guides (Figure 6-47, (1)) out of the cylinder head.
Figure 6-47
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 87
4TNE98 Engine
Figure 6-1
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 88
(1) Valve Cover Nut (2) Valve Cover Nut O-ring (3) Valve Cover
(4) Valve Cover Gasket (5) Rocker Arm Shaft (6) Rocker Arm Shaft Retaining Screw
(7) Cylinder Head Bolt (8) Glow Plug Harness (9) Valve Cap
(10) Valve Keepers (11) Spring Retainer (12) Valve Spring
(13) Valve Stem Seal (14) Valve Guide (15) Intake Valve
(16) Exhaust Valve (17) Cylinder Head Gasket (18) Cylinder Head
(19) Glow Plug (20) Glow Plug Cover (21) Push Rod
(22) Support Bracket Bolt (23) Rocker Arm Shaft Spring (24) Support Bracket Stud
(25) Support Bracket (26) Rocker Arm (27) Rocker Arm Shaft Retaining Ring
(28) Valve Adjusting Screw Lock Nut (29) Valve Adjusting Screw (30) Support Bracket Nut
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 89
Disassembly of Cylinder Head
Prepare a clean, flat working surface on a
workbench large enough to accommodate the
cylinder head assem bly. Discard all gaskets, O-rings
and seals.
CAUTION
Identify all parts and their location using an
appropriate meth od. It is important th at all parts
are returned to the same position during the
assembly process.
0000080en
1. Remove the intake manifold bolts (Figure 6-2,
(1)). Remove the intake manifold (Figure 6-2, (3)).
Discard the intake manifold gasket (Figure 6-2,
(3)).
Figure 6-2
2. Remove the exhaust manifold bolts (Figure 6-2,
(4)) and nuts (Figure 6-2, (5)). Remove the
exhaust manifold (Figure 6-2, (6)). Discard the
exhaust manifold gasket (Figure 6-2, (7)).
3. Remove the water pump from the engine. See
Disassembly of Engine Coolant Pump on 205.
4. Remove the fuel injec tors from the cylinder head.
See Removal of the Fuel Injec tors on page 196.
Removal of Glow Plugs
1. Remove the glow plug cover (Figu re 6- 3, (2))
from each of the glow plugs (Fig ure 6-3, (1)).
2. Disconnect t he glow plug har ness (Figure 6-3,
(3)) from the glow plugs.
3. Remove the glow plugs from the cyli nder head
(Figure 6-3, (4) ).
Figure 6-3
Removal of Valve Cover
1. Remove the valve cover nuts (Figure 6- 4, (1)).
2. Check the conditi on of t he O-ri ng (Fig ure 6-4, (2))
on each valve cover nut. Replace the O-ring if
necessary.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 90
Figure 6-4
3. Remove the valve cover (Fig ure 6-4, (3)). Discard
the valve cover gasket (Fig ure 6-4, (4)).
Removal of Rocker Arm Assembly
1. Remove the bolt (Figure 6- 6, ( 1) ) and loc ki ng
nuts (Figure 6-6, (2)) that retain the rocker arm
support brackets to the cylinder head.
2. Lift the rocker arm assembly fr om the c yli nder
head.
3. Lift the push rods from the cylinder head.
4. Number the push rods so that they are reinstalled
with the same valve tappet and rock er arm.
Figure 6-6
Disassembly of Rocker Arm Assembly
1. Remove the rocker arm shaft alignm ent screw
(Figure 6-7, (1) ) fr om the support br ac k et that
secures the rocker arm shaft (Figure 6-7, (2)).
2. Remove the retaining rings (Figure 6-7, (3)) from
the ends of the rocker arm shaft (Figure 6-7, (2)).
3. Slide the rocker arm shaft (Fig ure 6-7, (2)) out of
the rocker arm support brac k ets (Fig ure 6-7, (4)),
springs (Figure 6-7, (5)), and rocker arms (Figure
-7, (6)).
NOTE : The rocker arm shaft fits tightly in the rock er
arm support brackets. Cl am p the support br ac k et in
a padded vise and twist the rock er arm shaft to
remove. Reverse this process when you reinstall the
rocker arm shaft into the support br ac k ets.
NOTE : Mark the rocker arms so they can be
reinstalled wit h the original matching valve and
pushrod.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 91
Figure 6-7
4. .If necessary, remove the valve adjusting screw
(Figure 6-7, (7) ) and l oc k nut (Figu re 6- 7, (8))
from the rocker arm s.
Removal of Cylinder Head
1. Loosen the cylinder head bolts following the
sequence shown in (Figure 6-8).
1. Fan Side
2. Camshaft Side
Figure 6-8
2. Remove the cylinder head bolts (Figure 6-9, (1)).
3. Lift the cylinder head away from the cylinder block.
Discard the cylinder head gasket (Figure 6-9, (2)).
Position the cylinder head on the work bench to
prevent damage to t he combustion surface.
Figure 6-9
Removal of Intake / Exhaust Valves
1. Place the cylinder head on the work bench wit h
the combustion side down.
2. Using the valve spri ng c om pr essor tool, compress
one of the valve springs (Figure 6-10).
Figure 6-10
3. Remove the valve keepers (Figure 6-11, (2)) and
valve cap (Figure 6-10, (1)) from the end of the
valve.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 92
4. Slowly release the tension on the valve spring.
5. Remove the spring retainer (F ig ure 6-11, (3)),
valve spring (Figure 6-11, (4)) and valve stem
seal (Figure 6-11, (5)).
Figure 6-11
6. Repeat this procedure unt il all the intake and
exhaust valv e springs and v alve stem seals are
removed.
NOTE : If you are going to reinstall t he v alv es in the
cylinder head, m ar k them so they c an be installed in
their original location.
7. Turn the cylinder head so the exhaust port side
faces down. Remove the intake and exhaust
valves (Figure 6-11, ( 6)) from the cylinder head.
Removal of Valve Guides
1. Using a drift pin and hammer, drive the valve
guides (Figure 6-12, (1)) out of the cylinder head.
Figure 6-12
Cleaning of Cylinder Head Components
WARNING
FUME / BURN HAZARD!
Always read and follow safety related
precautions found on containers of hazardous
substances like parts cleaners, pri mers, sealants
and sealant removers.
Failure to comply could result in death or
serious injury.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 93
Thoroughly clean all c om ponents using a nonmetallic brush and an appropri ate solvent. Each part
must be free of carbon, metal fili ngs and other
debris.
Inspection of Cylinder Head
Components
Visually inspect t he parts. Replace any parts that are
obviously di scolored, heavily pitted or otherwise
damaged. Discard any parts that do not m eet its
specified limit.
CAUTION
Any part which i s found defective as a result of
inspection or any part whose measured value
does not satisfy the standard or limit must be
replaced.
CAUTION
Any part determined to not meet the service
standard or limit before the next service, as
determined from the state of current rate of wear,
should be replaced even though the part
currently meets the service standard limit.
Inspection of Push Rods
Push Rod Bend
1. Place the push rods on a flat inspection block or
layout bed.
2. Roll the push rods until a gap can be observ ed
between a portion of t he push rod and t he surf ace
of the block or layout bed.
3. Use a feeler gauge to measure the gap ( Fi gu re 6-
48). See Push Rod on page 68 for the servic e limit .
Figure 6-48
Inspection of Rocker Arm Assembly
Rocker Arm Shaft Hole Diameter
1. Use a telescoping gauge and mic r om eter to
determine if the insi de diameter of all the rocker
arm support brackets and the rock er arms (Figure
6-49) are within the specified limits. See Rocker
Arm and Shaft on page 68 for the service limit.
2. Inspect the contact areas (Figure 6-49, (1)) for
excessive wear or dam age.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 94
Figure 6-49
Rocker Arm Shaft Outside Diameter
Use a micrometer to measure the roc k er arm shaft
diameter (Figure 6-50). Measure at each r ocker arm
location in two dir ections 90° apart (Figure 6-50).
See Rocker Arm and Shaft on page 68 for the
ser vic e limit.
Figure 6-50
Inspection of Valve Guides
Valve Guide Inside Diameter
Visually inspect t he valve guides for distortions,
scoring or other damage.
NOTE : Measure the valve guides whil e they are
installed in cylinder head.
Use a telescoping gauge and mi c r om eter to
measure the inside di am eter at each end of the
valve guide. Measure in three places and 90° apart
(Figure 6-51). See Intake/Exhaust Valve and Guide
on page 67 for the service limit. Replace the valve
guides if not within specification.
Figure 6-51
Inspection of Cyli nd er Head
Cylinder Head Disto rt ion
Place the cylinder head fl at and inverted
(combusti on side up) on t he benc h. Use a straight
edge and feeler gauge to m easure cyl inder head
distortion (Figure 6-52). Measure diagonally and
along each side. See Cyli nder Head on page 66 for
the service limit .
Figure 6-52
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 95
If distortion exc eeds the service limit, resurface or
replace the cyli nder head. Remove only enough
material to make the cyli nder head flat, but do not
remove more than 0.008 in (0.20 mm).
Inspection of Intake and Exhaust Valves
Visually inspect t he intake and ex haust v alv es.
Replace any valves that ar e obv iousl y discolored,
heavily pitt ed or other wise damaged.
Valve Stem Diameter
Use a micrometer to measure the valve stem
diameter. Measure the valve stem near the
combustion end and near the opposite end (Figure
6-53, (1)). See Intake/Exhaust Valve and Guide on
page 67 for the service limit.
Figure 6-53
Valve Stem Bend
Place the valv e stem on a flat inspection block or
layout bed. Roll the valv e until a gap can be
observed between a portion of the valve stem and
the surface of the bloc k or bed. Use a feeler gauge
to measure the gap (Figure 6- 54) . See
Intake/Exhaust Valve and Guide on page 67 for the
ser vic e limit.
Figure 6-54
Valve Recession
NOTE: The valve guides must be installed t o
perform this check.
Insert the valves into their original locations and
press them down until they ar e fully seated. Use a
depth micrometer (F ig ure 6-55) to measure the
difference between the cyl inder head gasket surface
and the combustion surface of each exhaust and
intake valve (Figure 6-56). See Cyli nder Head on
page 66 for the service limit.
Figure 6-55
NOTE : 2-Valve cylinder head is shown. 4-Valve
cylinder head i s simil ar.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 96
Figure 6-56
Valve Face and Valve Seat
Always check the cl ear anc e between the valve and
valve guide before gri nding or lapping the valve
seats. See Intake/Exhaust Valve and Guide on page
67 for the service limit . If the clearance exceeds the
limit, repl ac e the valv e and/or valve guide to bring
the clearance within the limit.
Roughness or burrs will c ause poor seating of a
valve. Visually inspect the seating surfaces of each
valve and valve seat t o determi ne if lapping or
grinding is needed.
Visually inspect all valv es fac es and valve seats for
pitting, di stor tion, cracking, or evidenc e of
overheating. Usual ly the valves and valve seats can
be lapped or ground to return them to serviceable
condition. S ev er ely worn or dam aged c om ponents
will require r eplac em ent.
Coat the valve seat with a thin coat of bluing
compound. Install the valv e and r otat e to distribute
bluing onto the valv e face. The contact pattern
should be approximately centered on the valv e face
(Figure 6-57, (1) ) and ev en in width.
Figure 6-57
Also visually inspect the valve seat for even contact.
Light cutting can be performed by the use of a hand-
operated cutter (Fig ure 6-58).
Figure 6-58
Valve seat diameter can be adjusted by top-grinding
with a 150° stone to make the seat diameter smaller,
and bottom-grinding using a 40° stone to make the
seat diameter larger. Once the seat loc ation has
been corrected, gri nd and lap the seat angle (Figure
6-58, (1)) to specifi c ation. See Cylinder Head on
page 66 for specifications.
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 97
Grind the valve f ace and/or v alv e seat as necessary
to return them to servic eable condition. Grinding is
needed if the valv e and valve seat do not contact
correctly. Check the valve margin and valve
recession after grinding.
If the valve or seat require grinding, lap the valve
after grinding. Lap the valve face to the valve seat
using a mixture of valve lapping compound and
engine oil.
Be sure to thoroughly wash all parts to remov e all
grinding powder or compound.
Inspection of Valve Springs
Inspect the valve springs. If damage or corrosion is
seen, or if measurements exceed the specified limits,
replace the spri ngs.
Fractures
Check for fractur es on the insi de and outsi de
portions of the springs. If the valve spring is
fractured, replace the valve spring.
Corrosion
Check for corrosi on of spri ng material caused by
oxidation.
Squareness
Use a flat surface and a square to c hec k each
spring for squareness (Figure 6-59). See Valve
Spring on page 68 for the service limit.
Figure 6-59
Free Length
Use a caliper to measure the lengt h of the spring
(Figure 6-60). See Valve Spring on page 68 for the
ser vic e limit.
Figure 6-60
Inspection of Valve Bridges
4TNV98 Engine Only
Visually inspect t he contact surf ac e at both ends of
the valve bridge (Figure 6- 61, (2)) for excessive
wear or mushrooming.
Remove and inspect the seat (F igure 6-61, (1)).
Measure the diameter of t he v alv e bridge guide pin
bore in the valve bri dge and guide pin (Figure 6-61,
(3)). See Rocker Arm and Shaft on page 68 f or the
ser vic e limit.
Figure 6-61
4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 98
Reassembly of Cylinder Head
Use new gaskets, O-rings, and seals on reassembly
of the cylinder head.
IMPORTANT
Liberally oil all components during reassembly to
prevent prem ature wear or damage.
Reassembly of Valve Guides
1. The valve guides are installed into the cylinder
head with an extremely tight press fit. Before
installing the v alv e guides, place the valve guides
in a freezer for at least t wenty mi nutes This will
cause the valve gui des to c ontrac t, m aki ng it
easier to install the valve guides into place.
2. Immediately after r em ov ing the valv e guides from
the freezer, insert the valve guides (Figu re 6- 62,
(1)) in their proper positions.
4TNV98 Engine
4TNE98 Engine
Figure 6-62
3. Finish installing the valve guides (Figure 6- 63,
(1)) into the cylinder head to the proper height
(Figure 6-63, (3) ) using the valve guide installation
tool (Figure 6-63, (2)). See Intake/Exhaust Valve
and Guide on page 67.
Figure 6-63
Reassembly of Intake and Exhaust Valves
IMPORTANT
Always install new valve stem seals. The exhaust
valve seals can be identified by having yellow paint.
Ensure they are installed in the correct locations.
1. Oil the lip of the valve stem seal (Figure 6-64, (2)).
Using the valve stem seal installation tool (Figure
6-64, (1)), install a new v alv e st em seal on each of
the valve guides (Figure 6- 64, (3)).
Figure 6-64
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