YANMAR 4TNV98, 4TNE98 Service Manual

Service Manual

SB4319E00
Jan. 2008

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)

Important Safety Information

Most accidents involv ing product operation, maintenance and repair are caused by failure to observe basic
safety rules or prec autions. An ac cident can often be avoided by recognizi ng potentiall y hazardous situati ons
before an accident occurs. A person must be alert to potential hazards. This person should also have the
necessary trai ning, skills and tools to perf orm these functions properly.

Read and understand all safety p recautions and warnings before op erat in g o r performing lubrication,
maintenance and repair on this product.

Basic safety prec autions are listed in the “Saf ety” section of the Service or Technical Manual. Additional saf ety
precautions are listed in the “Safety” section of the owner/operation/maintenance publication.
Specific safety warnings f or all these publi cati ons are prov ided i n t he descripti on of oper ations where hazard s
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 the product labels are identified by the following symbol.

WARNING

Improper operation, lubrication, maintenance or repair of this product can be dangerous and could
result in in jury or death.
Do not operate or perfo rm any lubrication, main tenance or repair on this product, unt il you have read
and understood the operation, lubrication, maintenance and repair information.

Operations that may cause product damage are identified by NOTICE labels on the product and in this
publication.

DOOSAN cannot antici pate every possible circumstance that might involve a potential hazar d. 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 recomm ended by DOO SAN is used, you must satisfy yourself that i t is
safe for you and others. You should also ensure that the product wi ll not be damaged or made unsafe by the
operation, lubr ication, maintenanc e or r epair procedures you choose.

The information, specifications, and illustrations in this public ation are on the basis of information available at the
time it was written. The speci fications, 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.

1

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 M odel 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 Symbols.................................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 Peri odic Maintenance........... 40

Yanmar Replacement Parts.................... 40

Required EPA / ARB Maintenance-USA Only

.............................................................. 40

EPA / ARB Installation Requirements-USA

Only....................................................... 40

Periodic Maintenance Schedule.......................... 41

Periodic Maintenance Procedures ......................43

Drain Fue l F il te r / Water Sep a ra 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 Oper ation................ 51

Every 500 Hours of Oper ation................ 54

Every 1000 Hours of Oper ation.............. 59

Every 1500 Hours of Oper ation.............. 61

Every 2000 Hours of Oper ation.............. 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 Pist on 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 f or Bolts and Nuts....................... 73

Special Service Tools.......................................... 75

4TNV98 & 4TNE98 Diesel Engine 3 Index

Measuring Instrum ents........................................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 Camshaf t and Timing

Components..........................................111

Disassembly of Cr ank shaft and Piston

Components......................................... 116

Inspection of Cr ankshaft and Camshaft

Components.........................................120

Honing and Boring ................................126

Reassembly of Crankshaf t 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 Instrum ents......................................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 Injection Timing

Specification......................................... 157

Checkin g Fuel Injection Timing............. 158

Adjustin g Fu e l Inje ction Ti m ing............. 161

Fuel Injec to r s....................................................163

Removal of Fuel Injectors..................... 163

Testing o f Fuel In jectors....................... 164

Disassembly and Inspect ion of Fuel

Injectors............................................... 165

Adjustin g Fu e l Inje ctor Pressure........... 16 6

Reassembly of Fuel Injectors............... 167

Installation of the Fuel Injectors............ 167

4TNE98 ENGINE..............................................168

Fuel System Special Torque Chart........ 168

Measuring Instrum ents......................... 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 Prevention Mechanism

............................................................ 178

Fuel Injection Volume Adjustment

Mechanism .......................................... 178

Delivery Valve Assembly...................... 179

Delivery Valve Holder with Damping Valve

............................................................ 179

ll - Speed Governor........................................ 180

A

At Start of Engine................................. 182

During Idling......................................... 183

At Full-Load Maximum Speed Control.. 184
At No-Load Maximum Speed Control ... 185
Full-Load Posi tion Adjustment Mechanism

............................................................ 186

Stru c tu re And Ope r a tion Of Timer..................... 187

Standard T ype Au tomatic 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 Testi ng of the Fuel Injectors

............................................................ 197

Judgement Criteria on Atomization

Condition .............................................199

Installation of Fuel Injectors.................. 200

4TNV98 & 4TNE98 Diesel Engine 4 Index

Section 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 st em 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 Measuri ng Com pr ession

Pressure...........................................................236

Compression Pressure Measurement

Method................................................ 236

Quick Reference Table For Troubleshooting..... 239

Troubleshooting Charts..................................... 240

Wiring Diagram................................................. 243

4TNV98 & 4TNE98 Diesel Engine 5 Index

Section 1. GENERAL SERVICE INFORMATION

Component Identification

Figure 4-1a, Figure 4- 1b shows where the major

engine components are located.

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 Tank.
(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 S ervice Information 7

Locatio n of L ab els

Figure 4-2 shows the location of regulatory and

safety label s on Yanmar TNV & TNE series engi nes.

4TNE98 ENGINE

4TNV98 ENGINE

Figure 4-2

The typical locati on of the emission control
information label shown (F i 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 Regulat i ons - USA Only

Yanmar engines meet Environmental Protection
Agency (EPA) (U. S. Federal) emission control
standards as well as the Calif or nia Ai r Resourc es
Board (ARB, California) regulations. 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) in the Periodic
Maintenance Sc hedule section of this manual.

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 8

Emission Control Labels

Since emission cont r ol r egulations are being issued
on a global basis, it is necessary t o identify which
regulati ons a particular engine complies with. We
have listed sev eral different 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 in this manual have been
certifi ed by the 97/68/ E C Di r ec tive.

To identify the engines that meet this certif ic ation,
the 97/68/EC emission c ontrol label is affixed on
the engines

(97/68/EC)

Engine Family

The EPA / ARB labels and the 97/68/E C label all
have an Engine Family field. The following is an
explanati on of t he Engi ne Fami ly desi gnation:

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 9

Function of Major Engine Components

Components Functions

The air cleaner prevents airborne contaminants from entering the
engine. Since t he air cleaner is application specific, it must be carefully

Air Cleaner

Dipstick (Engine Oil )

Dipstick (Engine Oil )

Electric Fuel Pump
(If Equipped)

Engine Oil Filter

Engine Oil Cooler
(If Equipped)

Fuel Filter

Fuel Filter/ Water Separator

Fuel Priming Lever
(If Equipped)

Fuel Tank

Side and Top Filler Port
(Engine Oil)

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 filter element is necessary. See the Periodic Maintenance
Schedule on page 39 for the replac ement frequency.

The alternator is driven by a V-belt which is powered by the crankshaft
V-pulley. The alternat or supplies electricity to the engine systems and
charges the battery while the engine is running.

The engine oil dipstic k is used to determ ine the amount of engine oil in
the crankcase.

The electric fuel pump makes sure there is a constant supply of diesel
fuel to the fuel injec tion pump. The electric fuel pump is electr o-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 f uel pum p is install ed, turn
the key switch to the ON positi on for 10 to 15 seconds to prime the fuel
system.

The engine oil filter removes contaminants and sediments from the
engine oil. Periodic replacement of the engi ne oil filter is necessary. See
the Periodic Maintenance Schedule on page 39 for the replacement
frequency.

The engine oil cool er helps to keep the engine oil cool. Engine cool ant
from the cooling system is circulated through an adapter at the base of
the engine oil filt er assem bly and then returned to the coolant pump
inlet.

The fuel filter rem ov 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 “diesel” is implied throughout th is
manual when the word “fuel” is used.

The fuel filter / water separator removes 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 electri c
fuel pump. Periodically drain the water from the f uel filter / water
separator.

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 t he engine for the first time, if you run out of
fuel, or if fuel system service is performed. To prime the fuel system,
operate the fuel priming lever until the cup in the f uel filter is full of fuel.

The fuel tank is a reservoir that holds diesel fuel. When the f uel 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 injection
pump. When the injec tion pump pressure reaches a preset v alue, a relief
valve allows the excess f uel to be returned back to the fuel tank. The fuel
tank is a required engine com ponent.

You can fill the crankcase with engine oil from either the side or the top
filler port dependi ng upon whi c h one is most convenient.

The starter motor is powered by the bat tery. When you turn the key

Starter Motor

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 10

switch in the operat or’s console to the START position, the starter motor
engages with the ring gear installed on the flywheel and starts the
flywheel in motion.

Function of Cooling System Components

Components Functions

The TNV engine is liquid-cooled by means of a cooling system. The
cooling system c onsi sts of a r adiator, radiator cap, engine cooling
fan, engine coolant pump,thermostat, and reserve tank. Note that

Cooling System

Engine Cooling F an

Engine Coolant Pump

Radiator

Radiator Cap

Reserve Tank

Thermostat

all cooling syst em components are required for proper engine
operation. Since some of the components are application
specific, they must be carefully selected b y an application
engineer. The application specif ic items are not part of the
basic engine package as shipped from the Yanmar facto ry.

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 thr ough the radiator.
The engine coolant pum p circulates the engine cool ant through t he
cylinder bl ock and the cylinder head and returns the engine c oolant
to the radiator.
The radiator acts as a heat exchanger. As the engine coolant
circulates through the cylinder block it absorbs heat . The heat in the
engine coolant is di ssipated in the radiator. As the engine cooling fan
circulates ai r t hr ough the radiator, the heat is transferred to the air.
The radiator cap c ontrols the cooling system pressure. The cooling
system is pressurized t o r aise the boiling point of t he engine c oolant.
As the engine coolant t emperature rises, the system pressure and
the coolant vol ume increases. When the pressure reaches a preset
value, the rel ease valve in the radiator cap opens and the exc ess
engine coolant flows into the reserve tank. As the engine coolant
temperature is reduced, the system pressure and v olume is reduced
and the vacuum valve in the radiator cap opens allowing the engi ne
coolant to flow from the reserve tank back into the radiator.
The reserve tank contains the overflow of engine coolant f rom the
radiator. If you need to add engine coolant to t he system, add it to
the reserve tank; not the radiator.

A thermostat is placed in the cooling system to prevent the engine
coolant from ci r c ulating into the radiator until the engine coolant
temperature r eac hes a preset t emperature. When the engine is cold,
no engine coolant flows through the radiator. Once the engine
reaches its operating t em per ature, the thermostat opens and allows
the engine cool ant t o flow through the radiator. By letting the engine
warm up as quickly as possible, the thermostat reduces engine
wear, deposits and emissions.

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 11

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
No. 2-D, No. 1-D,
ASTM D975-94

EN590:96
ISO 8217 DMX International
BS 2869-A1 or A2

JIS K2204 Grade No.
2

KSM-2610 Korea
GB252 China

Additi ona l Techn ic a l Fue l Requirements

• 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 f uel should not exceed 0.05%
by volume.

• Keep the fuel tank and f uel -handli ng equipment clean at all
times.

• Poor quality fuel can reduce engine perf ormance and / or
cause engine damage.

• Fuel additives are not recommended. Some fuel additi ves 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.

Location
USA
European

Union

United
Kingdom

Japan

• 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 Met hyl Ester), collectively
known as FAME (Fatty Acid Methyl Esters), are
being used as extenders for mineral oil deriv ed
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 approved mineral oil derived
diesel fuel. S uc h bio-diesel fuels are known in the
marketplac e as B5 diesel fuels.

These B5 diesel fuels 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 pur c hased onl y from

recognized and author ized diesel fuel suppliers.

Section 1. Componen t Identification 12

Precautions and con cerns regarding the use of
bio-fuels:

1. Free methanol in FAME may result in corrosion of

aluminum and zinc FI E components.

2. Free water in FAME may result in plugging of fuel
filters and incr eased bact er ial growth.

3. High viscosity at low temper atures may result in
fuel deliv ery pr oblems, injection pump seizures,
and poor injection nozzle spray atomization.

4. FAME may have adverse effects on some
elastomer s (seal m aterials) and may result in fuel
leakage and diluti on of the engine lubricating oil.

5. Even bio-diesel fuels that comply with a suitable
standard as delivered, will require additi onal 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 f uels that do not comply with
the standards as agreed to by t he diesel engine
manufacturer s and the diesel fuel injection
equipment manufacturers, or biodiesel fuels that
have degraded as per the prec autions and
concerns above, m ay affect the warrant y
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, ci garette, 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 ign ite 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 S ervice Information 13

DANGER

FIRE AND EXPLOSION HAZARD

Diesel fuel is flammable and explosive under
certain conditions.

Before you operate the engine, check for fuel
leaks. Replace rubberized 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.

!

Figure 4-3

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 fu el system causing it
to clog.

Note that a typical f uel tank is shown. The fuel tank
on your equipment may be different.

1. Clean the area around the fuel cap (Figure 4-3,
(1)).

2. Remove the fuel cap (Figure 4-3, (1)) from the
fuel tank (Figure 4-3, (2)).

3. Observe the fuel lev el sight gauge (Figure 4-3,
(3)) and stop fueling when the gauge shows the

fuel tank is f ull. NEVER overfill the fuel tank.

4. Replace the fuel cap (Figu re 4-3, ( 1) ) and hand
tighten. Ov er-tightening the fuel cap will dam age
it.

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 14

Priming the Fuel System

The fuel system needs to be primed under certain
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 m aintenance such as changing

the fuel filter and draining the fuel filter / water
separator, or replacing a fuel system component .

To prime the f uel system on engines equipped with
an electric fuel pum p:

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 t he 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 ring gear.

To prime the f uel system on engines not equipped
with an electric fuel system:

1. Place an approv ed container under the air bleed
port.

2. Loosen the air bleed port (Figure4-4, (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 ring gear.

Figure 4-4

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 15

Engine Oil

CAUTION

Only use the engine oil specified.
Other engine oils may affect warranty coverag e,

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 classifi c ations:

Service Catego ries

• API Service Categories CD or higher

• ACEA Service Categories E-3, E-4, and E-5

• JASO Service Category DH-1

Definitions

• API Classification (American Petroleum Institute)

• ACEA Classification (Association des
Constructeurs Europée ns d'Automobilies)

• JASO (Japanese Automobile Standards
Organization)

NOTE:

• Be sure the engine oil, engi ne oil storage
containers, and engine oil filling equipment arefree
of sediment and water.

• Change the engine oil after the first 50 hours of
peration and then ev ery 500 hours thereafter.

• Select the oil vi scosity based on the ambient
temperature where the engine is being operat ed.
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 appropr iate 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 S ervice Information 16

Checking Engine Oil

1. Make sure the engi ne is level.

2. Remove the dipstick (Figure 4-5, (1)) and wi pe it

with clean clot h.

3. Fully reinsert the dipstick.

4. Remove the dipstick. The oil level shoul d be
between the upper (F igure 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 engi ne 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 port (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. Over-tightening may damage t he 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 operati on m anual pr ov ided
by the driven machine m anufacturer for the actual
engine oil capacity of your machine.

The following ar e the engine oil capacities for
various Yanmar engines.

Engine Model

4TNV98

4TNE98

Dipstick Upper

Limit / Lower Limit

11.1 / 6.3 qt

(10.5 / 6.0 L)

9.7 / 7.6 qt

(9.2 / 7.2 L)

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 17

Engine Coolant

DANGER

CAUTION

SCALD HAZARD!

NEVER remove the radiator cap if the engin e 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.

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 intern al 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.

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 18

Engine Coolant Specifications

Use a Long Life Coolant (LLC) or an Ext ended Life
Coolant (ELC) that meets or exceeds the f ollowing
guidelines and specifications:

Additi ona l Techn ic a l C oolant
Specifications:

• ASTM D6210, D4985 (US)

• JIS K-2234 (Japan)

• SAE J814C, J1941, J1034 or J2036 (Int ernational )

Alternative En gi 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 cool ant
(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 is flushed. Note that a typical
radiator is illustrated (Figure 4-6) .

Figure 4-6

1. Check to be sure the radi ator drain plug
isinstalled and tightened or the drain cock(Figure
4-6, (1)) is closed. Also make sure thecoolant

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 t he oil c ooler.

Figure 4-7

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 19

Figure 4-8

2. Remove the radiat or cap (Fig ure 4-6, (2)) by
turning it counter-clockwise about 1/3 of a turn.

3. Pour the engine coolant slowly into the radiator
until it is even wit h the lip of the engine coolant
filler port. Make 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 radiat or c ap with
the notches on the engine c oolant filler port.
Press down and turn the cap cl oc 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)) wit h 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 c onnec ted and there are no
cracks or damage. If the hose is damaged, the
engine coolant will leak out instead of going into
the reserve tank.

7. Run the engine until it is at oper ating temperatur e.
Check the level of engine coolant in the reserve
tank. When the engine is runni ng and the engine
coolant is at normal temperature, the coolant
level in the tank should be at t he FULL (HOT)
mark (Figure 4-6, (6)). If the engi ne coolant 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 ar e for the engineonly

without a radiator. Refer to theoperation manual
provided by the drivenmachine manufacturer for the
actualengi ne c oolant capacity on yourmachine.

The following ar e the engine coolant capacities for
various Yanmar engines.

Engine Model

4TNV98 4.4 qt (4.2 L)

4TNE98 4.4 qt (4.2 L)

Engine Coolant

Capacity

Specifications

Description of Model Number

When ordering parts or making an inqui ry about the
engine you are working on, be sure to include 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 S ervice Information 20

Engine General Specifications

Type

Combustion
System

Starting System Electric Starting

Cooling System Radiator
Lubricating

System
PTO Position Flywheel End
Direction of

Rotation

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 provi ded
by the driven machine m anufacturer. Engine rating
conditions are as foll ows (SAE J1349, ISO 3046/1):

• Atmospheric Condition: Room temperat ur e 77°F

(25°C), Atmospheri c pr essure 29.53 in Hg (100
kPa, 750 mm Hg), Relative humidity 30%

• Fuel Temperatur e at F uel Injector Pump Inlet:

104°F (40°C)

• With Cooling Fan, Air Cl eaner, Muffler: Yanmar

Standard

• After Engine Break -In Period; Output Allowable

Deviation: ± 3%

• 1 PS = 0.7355 kW

• 1 hp SAE (Society of Automotive Engineers) =

0.7457 kW

Vertical In-line, Water Cooled,
4-Cycle Diesel E ngine

4TNV98 Direct Injection
4TNE98 Indirect Injection

Forced Lubri c ation with
Trochoid Pump

Counterclock wise Viewed from
the Flywheel End

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 21

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

Max. Rated Output (Net )

High Idling RPM 2400±25
Engine Weight (Dry)

with Flywheel Housing
PTO Position Flywheel End (Option)

Direction of Rotation Counterclock wise Viewed from Flywheel End
Cooling System Liquid-Cooled with Radiator
Lubricating System Forced Lubri c ation with Trochoid Pump

Normal Oil Pressure at
Rated Engine Speed
Normal Oil Pressure at
Low Idle Speed

Electric Starting - Starter Motor: DC12V, 3.1 hp (2.3 kW)**

Starting System

Recommended Batter y Capacity: 12V, 64 Amp-Hour (5h rating)**
Dimensions (L × W × H)*
Engine Oil Pan 11.1 / 6.3 qt (10.5 / 6.0 L) (Dipstick Upper Limit / Lower Limit)

hp SAE 61.2

kW 45.6
PS 62.0

518.2 lb (235 kg)

42 - 57 psi (0.29 - 0.39 MPa, 2.96 - 3.98 kgf/cm²)

8.5 psi (0.06 MPa, 0.6 kgf/cm²)or greater

Alternat or: DC12V, 40A**

28.31 x 19.61 x 29.21 in.
(719 x 498 x 742 mm)

Engine Coolant Capacit y 1.1 gal (4.2 L) Engine Onl y
Standard Cooling Fan 16.14 in. (410 mm) O.D., 6 Bl ade P usher-Type**

* Engine specific ations without radiator
** 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 your machine.

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 22

4TNE98 EPA Tier 3

Engine Model 4TNE98 EPA Tier 3
Version VM (BQDF(C))
Type Vertical Inline Diesel Engine
Combustion System Indirect Injection, No Turbocharger
Aspiration Natural
No. of Cylinders 4
Bore × Stroke 3.86 x 4.33 in. (98 x 110 mm)
Displacement 202.5 cu in. (3.319 L)

RPM

-1

(min

)

**Max. Rated Output
(Gross)

hp SAE 58.6

kW 43.7
PS 59.4

High Idling Speed
(Bare Engine)
Low Idling Speed
(Bare Engine)

2625±25

850±25 rpm

Engine Weight (Dry) * 496 l b ( 235 k g)

2300

PTO Position Flywheel Side
Direction of Rotation Counterclock wise Viewed From Flywheel Side
Cooling System Liquid-Cooled With Radiat or

Forced Lubri c ation With Trochoid Pump

Lubricating Sy st em

At normal operati ng speeds, oi l pressure is: 42-57 psi

(0.29 - 0.39 MPa; 3.0 – 4.0 kgf/cm²)

At idle, oil pressure is: No less than 18.5 psi (0.13 Mpa; 1.3kgf/cm ² )

Electric Starting - Starter Motor: DC12V, 3.1 hp (2.3 kW)

Starting System

Alternat or: DC12V, 80A

Recommended Batter y Capacity: 12V, 622 CCA

(Cold Cranki ng Amps)

Dimensions (L × W × H)*
Engine Oil Pan Capacity

(Dipstick Upper Limi t / Lower Lim it)

28.0 x 20.3 x 29.8 in.

(710 x 516 x 758 mm)

9.7 / 7.6 qt (9.2 / 7.2 L)

Engine Coolant Capacit y 1.11 gal (4.2 L) Engine Only

* Engine Specifications Without Radiator, Muffler, and Air Cleaner.
** The Intake and Exhaust conditi on of M ax. Rated output are

Air Intake Restri ction : 250mm A q

Exhaust Gas Restriction : 1000mmAq

***The detail specific ations are refer to the Specification docum ent which is agreed between both engineering.

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 23

Engine Service Standards

Inspection Item Standard Limit

Intake / Exhaust Valve Clearance

0.006 - 0.010 in.

(0.15 - 0.25 mm)

Reference

page

See Measuring

-

and Adjusting

Valve Clearance

on page 104

Fuel Injection

Timing

Fuel Injection

Pressure

Compression

Pressure at 250

rpm 250 min¯¹)

Deviation Bet ween Cyli nders

Oil Pressure Switc h Operating Pressure

Lubricating Oil

Pressure

Thermostat

4TNV98 See Checking and Adjusting Fuel Injection Timing on page 157.
4TNE98 8.5°±1° ATDC ­4TNV98 See Test and Adjustment Specifications on page 144.

4TNE98

4TNV98

4TNE98

Max.(when cold)

At rated Output

When idling

Option

Standard

1711-1842 psi

(11.8 - 12.7 Mpa;

120 - 130 kgf / cm²

483 - 513 psi

(3.33 - 3.53 MPa;

34 - 36 kgf / cm²)

425 - 428 psi

(2.93 – 2.95 MPa;

29 - 31 kgf / cm²)

29 - 43 psi

(0.2 - 0.3 MPa;

2 - 3 kgf/cm²)

5.8 - 8.8 psi

(0.04 - 0.06 MPa;

0.4 - 0.6 kgf / cm²)
86 psi

(0.59 MPa;

6.0 kgf / cm²)
42 - 57 psi

(0.29 - 0.39 MPa;

2.96 - 3.98 kgf / cm²)

8.5 psi

(0.06 MPa;

0.6 kgf / cm²)

or greater

Valve Opening

Temperature

157°F - 163°F

(70°C - 73°C)

176°F - 183°F

(80°C - 84°C)

- -

384 - 414 psi

(2.65 - 2.85 MPa;

27 - 29 kgf / cm²)

341 psi

(2.35 MPa;

24 kgf / cm²)

- -

- -

- -

- -

- -

Full Opening Lift

Temperature

0.32 in (8 mm) or
Above

185°F (85°C)

0.39 in (10 mm)
or

above

203°F (95°C)

With Plunger Lifted

0.039 in (1mm)

See

Troubleshooting

By Measuring

Compression

Pressure on

page 236

-

See Thermostat

on page 207

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 24

Tightening Torques for Standard
Bolts and Nuts

Use the correct amount of torque when you tighten
the fasteners on the machine. Applying excessive
torque may damage t he fastener or c om ponent and
not enough torque may cause a leak 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 S ervice Information 25

Item

Hexagon Bolt (7T) and
Nut

PT PLug

Item

Pipe Joint Bolt

Nominal Thread
Diameter x Pitch

M6 x 1.0 mm

M8 x 1.25 mm

M10 x 1.5 mm

M12 x 1.75 mm

M14 x 1.5 mm

M16 x 1.5 mm

1/8 mm
1/4 mm
3/8 mm
1/2 mm

Nominal Thread
Diameter x Pitch

M8

M10

M12

M14

Tightening T orque Remarks
7 - 9 ft·lb

(87 -104 in·lb,

9.8 -11.8 N·m,

1.0 -1.2 kgf·m)
17 - 21 ft·lb
(200 - 251 in.·lb,

22.6 - 28.4 N·m,

2.3 - 2.9 kgf·m)
33 - 40 ft·lb
(44.1 - 53.9 N·m,

4.5 - 5.5 kgf·m)
58 - 72 ft·lb
(78.4 - 98.0 N·m,

8.0 - 10 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.

94 - 108 ft·lb
(127.5 - 147.1 N·m,
13 - 15 kgf·m)
159 - 174 ft·lb
(215.7- 235.4 N·m,
22 – 24 kgf·m)
7 ft·lb (87 in.·lb,

9.8 N·m, 1.0 kgf·m)
14 ft·lb (173 in.·l b,

19.6 N·m, 2.0 kgf·m)
22 ft·lb
(29.4 N·m, 3.0 kgf·m)
43 ft·lb
(58.8 N·m, 6.0 kgf·m)

Tightening T orque Remarks
9 - 12 ft·lb

(112 - 148 i n.·lb,

12.7 - 16.7 N·m,

1.3 - 1.7 kgf·m)
14 - 19 ft·lb
(173 - 225 in.·lb,

19.6 - 18.734 N·m,

2.0 - 3.5 kgf·m)
18 - 25 ft·lb
(24.5 - 34.3 N·m,

.

2.5 - 3.5 kgf·m)
29 - 36 ft·lb
(39.2 - 49.0 N·m,

4.0 5.0 kgf·m)
36 - 43 ft·lb

M16

(49.0 - 58.8 N·m,

5.0 - 6.0 kgf·m)

NOTE: Torque values shown in t his manual are for clean, non-lubric ated fasteners unless otherwise specified.

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 26

Abbre viations an d Sym bo ls

Abbreviations.

A ampere
AC alternating current
ACEA Association des Constructeurs

Européens d’Automobilies

Ah ampere-hour
API American Petroleum I nsti tute
ARB Air Resources Board
ATDC after top dead center
BDC bottom dead center
BTDC before top dead center
°C degree Cels i us
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 injection
DVA dir ect volt adapter
EPA Env i ronmental Pr otection Agency
ESG elect ron ic speed govern or
°F degree Fahrenheit
fl oz fluid ounce (U.S.)
fl oz/min f l uid ounce (U.S.) per minute
ft foot
ft-lb foot 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 iam eter
ID identification
IDI indirect injection
in. inch
in.Aq inches Aqueous (water)
in.Hg inches M ercury
in.-lb inch pound
j joule

JASO
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 Soc iety of Automotiv e Engi neers
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

Japanese Automobil e Standards
Organization

Symbols

°
+

­±
Ω
μ
%

degree
plus
minus
plus or minus
ohm
micro
percent

4TNV98 & 4TNE98 Diesel Engine Section 1. General S ervice Information 27

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)
hp
(metric
or PS)
hp SAE x 1.0138697 =hp(metric

hp SAE x 0.7456999 = kW
kW x 1.3596216 =hp(metric

kW x 1.3410221 = hp

x 0.9863201 = hp SAE

x 0.7354988 = kW

or PS)

or PS)

SAE

Units of Temperature

°F = (1.8 x °C) + 32

4TNV98 & 4TNE98 Diesel Engine Section 1. General Service Information 28

°C = 0.556 x (°F - 32)

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 th e engine.
NEVER jump-start the engine. Sparks caused by

shorting the battery to the starter termin als 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 spu rt 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 fuel. Filling the
fuel tank with gasoline may resu lt i n a fire and
will damage the engine.

NEVER refuel with the engine running.
Wipe up all spills immediat ely.
Keep sparks, o pen 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 29

DANGER

FIRE AND EXPLOSION HAZARD!
Diesel fuel is flammable and explosive under

certain conditions.
Before you operate the engine, check for fuel

leaks. Replace rubb erized fuel hoses every two
years or every 2000 hours of engine operation,
whichever comes first, even if the engine has
been out of service. Rubb erized 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

DANGER

FIRE AND EXPLOSION HAZARD!

Diesel fuel is flammable and explosive under
certain conditions.

Be sure to place the diesel fuel contain er 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 t o
the engine during engine operation or shortly
after shutdown.

Failure to compl y will result in death or serious
injury.

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.

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. Period ic Maintenance 30

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 serious 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 an ce (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 component.

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 und er the air bleed
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 t he 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 fu el pump to prime th e 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 31

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 combu stion 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 in jur y .

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 engi ne is running.

Remove all jewelry before you operate or
service the machin e.

NEVER start the engine in gear. Sudden
movement of the engine and/or machine 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 clear of the 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 fro m the area.

Failure to comply could result in death or
serious in jur y .

4TNV98 & 4TNE98 Diesel Engine Section 2. Period ic Maintenance 32

WARNING

SUDDEN MOVEMENT HAZARD!

Engaging the transmission or PTO at an
elevated engine speed could result in
unexpected mo vement of th e equ ip ment.

Failure to comply could result in death or
serious in jur y .

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 while the engin e is operating an d
could seriously burn you.

Failure to comply could result in death or
serious in jur y .

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 in jur y .

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 33

WARNING

EXPOSURE HAZARD!

Wear personal protective equipment such as
gloves, work shoes, eye and hearing pro tection
as required by the task at hand.

NEVER wear jewelry, unbuttoned cuffs, ties or
loose-fitting clothing when you are working
near moving/ro tating parts such as the cool ing
fan, flywheel or PTO shaft.

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 in jur y .

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 treat ment.

Failure to comply could result in death or
serious in jur y .

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 indust rial engine
dealer or distributor repair the damage.

Failure to comply could result in death or
serious in jur y .

4TNV98 & 4TNE98 Diesel Engine Section 2. Period ic Maintenance 34

WARNING

SHOCK HAZARD!

Turn off the battery switch (if equipped) or
disconnect the negative battery cable before
servicing th e 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 in jur y .

WARNING

ENTANGLEMENT HAZARD!
Stop the engine befo re you begin t o servi ce it.
NEVER leave the key in the key switch when

you are servicing the engine. Someone may
accidentall y start the eng ine 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 in jur y .

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 ned.

ALWAYS wear eye protection .
Failure to comply could result in death or

serious in jur y .

WARNING

BURN HAZARD!

Wait until the engine cools before you drain the
engine cool ant. Hot engine coolant may spl ash
and burn y ou.

Failure to comply could result in death or
serious in jur y .

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 35

CAUTION

COOLANT HAZARD!

Wear eye protection and rubber gloves when
you handle long life or extended life engine
coolant. If contact wit h 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

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 b y Yanmar
for the best engine performance, to prevent
engine damage and to comply with EPA/ARB
warranty requi rements.

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 i t 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 contamin ating 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 contamin ating the
engine cool ant. 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 af fect the properties of the
engine coolant.

CAUTION

NEVER attempt to modify the engine’s design
or safety features such as defeating the 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 repl acement parts.

4TNV98 & 4TNE98 Diesel Engine Section 2. Period ic Maintenance 36

CAUTION

Observe the following environmental operating
conditions to maintain engine performance and
avoid prematu re engine wear:

• Avoid operating in extremel y dusty condition s.

• Avoid operating in th e presence 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 p recautions are taken to avoid
being subject to a flood.

• NEVER expose the engine to the rain.

CAUTION

Observe the following environmental operating
conditions to maintain engine performance and
avoid prematu re engine 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 engin e 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 ran ge.

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
turbocharg er (if equipped) and exhaust system,
to cool slightly before the engine itself is 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 g reater 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 seriou s engine damage.

CAUTION

NEVER hold the key in the START position for
longer than 15 seconds or the starter moto r will
overheat.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 37

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 pressure, diesel
fuel leaks, engin e oil leaks, coolant leaks, and
for proper operation of the indicators and/or
gauges.

• During the first hou r of operation, 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 speeds and
loads for the next four to five hours.

• During the break-in peri od, carefully observe

the engine oil pressure and engine
temperature.

• During the break-in peri od, check the engine

oil and coolant level s f requently.

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 perform daily checks.
Periodic maintenance prevents unexpected

downtime, redu ces the number 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 eng in e coolant. Consult th e local
authorities or reclamation facilit y.

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 environment.

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 ip st ick.

4TNV98 & 4TNE98 Diesel Engine Section 2. Period ic Maintenance 38

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 performan ce 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 saf et y and perf ormance characteristi cs,
shorten the engine’s life and may affect the
warranty coverage on your engine.

See Yanmar Limited Warranty in Warranty
Section.

Consult your authorized Yanmar dealer or
distribu tor 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 drain co ck is op ened. If t his 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 ent er the engine and damage it.

CAUTION

The maximum air in take restriction, in t erms of
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
restrictio n exceed s t he above mentioned value.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 39

Introduction

This section of t he Servic e M anual describes the
procedures for pr oper c ar e and m aintenance of the
engine.

The Importance of Periodic
Maintenance

Engine deterioration and wear occurs in proportion
to length of time the engine has been in service and
the conditions the engine is subject to during
operation. P eriodic maintenance prevents
unexpected downtime, reduces the number of
accidents due to poor machine performance and
helps extend the life of the engi ne.

Performing 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 combu stion 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 in jur y .

Yanmar Replacement Parts

Yanmar recommends that you use genuine Yanm ar
parts when replacement parts are needed. Genuine
replacement parts help ensure l ong engine life.

Required EPA / ARB Maintenance-USA
Only

To maintain optim um engi ne performance and
compliance with the Environmental Protecti on
Agency (EPA) Regulations Non-road Engines and
the California Air Resources Board (ARB,
Californi a), it is essential that you follow the
Periodic Maintenance Schedule on page 41 and
Periodic Maintenance Procedures on page 43.

EPA / ARB Installation Requirements­USA Only

The following ar e the installation requirem ents for
the EPA / ARB. Unless these requirements are met,
the exhaust gas emi ssions will not be within the
limits specifi ed by the EPA and ARB.

Maximum Exhaust G as 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 el em ent if the air intake restriction
exceeds the abov e menti oned v alue.

Perform periodic maintenance procedures in an
open, level area free f rom traffic. If possible,
perform the pr oc edur es i ndoor s to pr ev ent
environmental condi tions, such as rain, wind, or
snow, from damaging the machine.

4TNV98 & 4TNE98 Diesel Engine Section 2. Period ic Maintenance 40

Periodic Maintenance Schedule

Daily and periodic maintenance is important to keep
the engine in good operating condition. The
following is a summary of maintenance items by
periodic maintenance intervals. P eri odic
maintenance int ervals vary depending on engi ne
applicati on, loads, diesel fuel and engine oil used
and are hard to establish definitively. The following
should be treated only 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 saf et y and perf ormance characteristi cs,
shorten the engine’s life and may affect the
warranty coverage on your engine.

See Yanmar Limited Warranty in Warranty
Section.

Consult your authorized Yanmar dealer or
distribu tor fo r assistance when checking items
marked with a.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 41

○:Check ◇:Replace

System Check Item

Check and Refill Engine Cool ○
Check and Clean Radiator Fins ○

Check Engine Coolant T e mp.
Indicator

Cooling
System

Cylinder
Head

Check and Adjust Cooling Fan V-Belt

Drain, Flush and Refill Cooling
System with New Coolant

Adjust Intake / Exhaust Valve
Clearance

Lap Intake / Exhaust Valve Seats ○

Periodic Maintenance Interval

Every

Daily

hours

○

○1st

time

○

50

Every

250

hours

○

2nd
and

after

Every

500

hours

Every

1000

hours

◇ or

every year

whichever

comes first

Every

1500

hours

Every

2000

hours

Electrical
Equipment

Engine Oil

Engine
Speed
Control
Emission
Control
Warranty

Fuel

Hoses
Intake and

Exhaust
Complete
Engine

Check Indi cators ○
Check Battery ○
Check Engine Oil Level ○
Check Engine Oil Pressure Indicator ○
Drain and Fill Engine Oil

Replace Engine Oil Filter

Check and Adjust Governor Lever
and Engine Speed Control

Inspect, Clean and Test Fuel Injectors ○
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 ○
Replace Fuel Filter ◇

Replace Fuel System and Cooling
System Hoses

Clean or Replace Air Cleaner Element ○ ◇
Overall Visual Check Daily ○

◇1st

time

○ ○

◇

2nd
and

after

every 2

NOTE: These procedures are consider ed nor mal maintenance and are performed at the owner’s expense.

○ or
years

4TNV98 & 4TNE98 Diesel Engine Section 2. Period ic Maintenance 42

Periodic Maintenance Procedures

Daily

4TNE98 For D25S-5 Only

WARNING

Perform the following procedures daily.

• Drain Fuel Filter / Water S epar ator

• Check Fuel Hoses and Engine Cool ant Hoses

Drain Fuel Filter / Water Separator

DANGER

FIRE AND EXPLOSION HAZARD!

• Diesel fuel is extremely fl ammabl e and

explosive und er certain conditions.

• When you remove any fuel system compo nent
to perform maintenance (such as changing the
fuel filt er) place an app roved container under
the opening to catch the fuel.

• NEVER use a shop rag to catch the fuel. Vapors
from the rag are extremel y flammable and
explosive.

• Wipe up any spills immediately.

• Wear eye protection. The fuel syst em is under
pressure and fu el could spray ou t when you
remove any fuel system component.

• Failure to comply will result in death or serious
injury.

0000009en.

HIGH PRESSURE HAZARD!

• Avo id skin contact with high pressure diesel

fuel spray caused by a fuel system leak such as
a broken fuel injecti on lin e. High pressure fuel
can penetrate your skin and result in serious
injury. If you are exposed to high pressure fuel
spray obtain prompt medical t reat ment.

• NEVER check for a fuel leak with your hands.
ALWAYS u se a pi ece of wood o r cardboard.
Have your authoriz ed Yanmar industrial engine
dealer or distributor repair the damage.

• Failure to comply could resu lt in death or
serious in jur y.

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
counterclo ckwise 2-3 turn s.This may occu r 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 43

CAUTION

Be responsible to the environment.
Follow these procedures for hazardous waste

disposal. F ailure to follo w these pro cedures may
seriously harm the environment.

• Follow the guidelines of the EPA or other
governmental agency for the proper di sposal of
hazardous materials such as engine oil, diesel
fuel and engine cool ant . Consult the local
authorities or reclamation facilit y.

• NEVER dispose of hazardous materials
irresponsibly by dumping them into a sewer, on
the ground or into ground w at er or waterways.

0000013en.

1. Position an approved container under the fuel
filter / water separator (Figure5-1, (1)) to collec t
the contaminants.

2. Loosen the drain cock (Figure5-1, (2)) at the
bottom of the fuel filter / water separator. Drain
any water collect ed insi de.

3. Hand tighten the dr ain cock.

4. Be sure to prime the diesel f uel system when you

are done. See Priming the Fuel System 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.

NEVER wait until the scheduled periodi c
maintenance if the fuel filter indicator comes on.

The fuel filter / water separator contains a sensor to
detect the amount of water and contaminants. This
sensor sends a signal t o an indic ator to alert the
operator.

Drain the fuel filt er / water separator as follows:

Figure 5-1

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 44

Daily

After Initial 50 Hours of Operation

Perform the following maintenance after the initi al
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 ned.

ALWAYS wear eye protection .
Failure to comply could result in death or

serious in jur y .

WARNING

SUDDEN MOVEMENT HAZARD!
Engaging the transmission or PTO at an

elevated engine speed could result in
unexpected mo vement of th e equ ip ment.

Failure to comply could result in death or
serious in jur y .

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 contamin ating 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 eng in e coolant. Consult th e local
authorities or reclamation facilit y.

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 environment.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 45

The engine oil in a new engine becomes
contaminated from 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 engi ne 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 allow the
engine oil to drai n more easi ly.

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·l b ( 53.9 - 63.7 N·m; 5. 5

- 6.5 kgf·m).

8. Dispose of used oil pr oper ly.

Remove the engine oil filter as follows:

1. Turn the engine oil filter (Figure 5- 2, (2) )

counterclockwise (Figure 5-2, (3)) usi ng 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 ( Figure 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

46

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 ip st ick.

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 t he
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 spill ed, 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 sufficient power. Also, the engi ne will
overheat due to the engine c oolant pump pulley
slipping.

Check and adjust the V-belt tension (defl ec 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 posi tions to check for V-belt
tension (Figure 5-4, (A), (B) and (C)). You can
check the tension at whichever position is the
most accessibl e. 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)

NOTE: A “Used V-Belt” refers to a V-belt which has
been used on a running engine for five minutes or
more.

1/4 - 3/8 in.

(7 - 10 mm)

Figure 5-4

5/16 - 1/2 in.

(9 - 13 mm)

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 47

2. If necessary, adjust the V-belt tension. Loosen

the adjusting bolt (Figure 5-5, (1)) and move the
alternator (Figure 5-5, (2)) wit h a pry bar (Figure
5-5, (3)) to tighten the V-belt to the desired
tension. Then tight en 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 groov e,
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

6. After adjusting, run the engine for 5 minutes or

more. Check the tensi on 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 maintenance
procedures, perform the following procedures every
50 hours thereafter.

• Drain Fuel Filter / Water S epar ator

• Check Battery

Drain Fuel Filt er / Water Separator

4TNV98 & 4TNE98 (For Chin a) 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 an ce (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 component.

Failure to compl y will result in death or serious
injury.

A B C

5/16 - 7/16 in.

(8 - 12 mm)

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance

3/16 - 5/16 in.

(5 - 8 mm)

1/4 - 7/16 in.

(7 - 11 mm)

48

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 drain co ck is op ened. If t his 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 eng in e coolant. Consult th e local
authorities or reclamation facilit y.

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 environment.

Drain the fuel filt er / water separator whenever
there are contami nants, such as water, collected in
the bottom of the cup. NEVER wait until the
scheduled periodic maintenance if contaminants
are discover ed.

The cup of the separator is made fr om semi­transparent materi al. In the cup is a red colored
float ring. The fl oat 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 separators are
equipped with a sensor to detect the amount of
contaminants. This sensor sends a signal to 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 collect ed 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 drain co ck is op ened. If t his 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 f uel 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 49

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 treat ment.

Failure to comply could result in death or
serious in jur y .

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 eng in e coolant. Consult th e local
authorities or reclamation facilit y.

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 environment.

When the amount of fl uid near s the lower l im i t

(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 wit h insufficient batter y fluid,
the battery life is shortened, and the battery m ay
overheat and explode. During the summer, check
the fluid level more often than specified.

Figure 5-8

If the engine cranking speed is so slow that the
engine does not start, rechar ge the battery.

If the engine still will not start after charging, have
your authorized Yanmar industrial engine dealer or
distributor check the battery and the engi ne’s
starting system.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance

50

If operating the machine where the ambient
temperature c ould drop to 5°F (-15°C) or less,
remove the battery from the mac hine at the end of
the day. Store the battery 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 an ce (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 component.

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 eng in e coolant. Consult th e local
authorities or reclamation facilit y.

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 environment.

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 (Figure 5-9, (3)).

3. Remove the drain plug (Fig ure 5-9, (2)) of the

fuel tank to drain the contami nates (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 fl ows out. Reinstall and tighten the
drain plug firml y.

5. Reinstall the fuel cap.

6. Check for leaks.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 51

Check and Clean Radiato r 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 to the radiator fins reduce
the cooling perf ormance, causing overheating.
Make it a rule to check the radiator 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 the compressed air.

• If there is a large amount of contamination on the
fins, apply detergent, thoroughly clean and rinse
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 aft er 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 l ev er and engi ne speed cont r ol
(throttl e lev er, pedal, etc.) of the machine are
connected together by a thr ottle cable or rod. If the
cable becomes stretc hed, or the connections
loosen, the gov ernor lever may not respond 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 governor lever or stretch the
cable and cause irr egular operation of the engine
speed control.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance

52

Checking and adjusting the governor lev er:

1. Check that the gover nor lever (Figure 5-11, (1))

makes uniform c ontact wit h 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 cable.

3. In some engine speed contr ol applications,

loosen the throttle cable lock nut (Figure 5- 11,
(4)) and adjust the cable so the governor lev er
makes proper contact with t he 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 performan ce 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 el em ent is clogged with dust.
Be sure to clean the air fil ter element periodically.

1. Unlatch and remov e the air cleaner cover

(Figure 5-12, (1) ).

Figure 5-12

2. Remove the element (Fi gu re 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 53

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 i s equi pped with a double

element, only rem ov e and r eplac e the inner
element (F ig 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 acing 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, ex c essively dirty or oily.

7. Clean inside of the air cleaner cover.

8. Install the element i nto t he air cleaner case

(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 (Figure 5-12, (6)).

10. Latch the air cleaner c over 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 ent er the 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 contamin ating 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 eng in e coolant. Consult th e local
authorities or reclamation facilit y.

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 environment.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance

54

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 Filter on page 45.

Replace Air Cleaner Element

CAUTION

The maximum air in take restriction, in t erms of
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
restrictio n exceed s t he above mentioned value.

Replace the air cleaner element (Figure 5- 12, (2) )
every 500 hours even if it is not damaged or dir ty.

When replacing the element, clean the inside of the
air cleaner case (F igu re 5- 12, (4)).

If the air cleaner is equipped with a double element,
only remove and repl ac 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 Filt er

DANGER

FIRE AND EXPLOSION HAZARD!

Diesel fuel is flammable and explosive under
certain conditions.

When you remove any fuel system component
to perform mainten an ce (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 component.

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
turbocharg er (if equipped) and exhaust system,
to cool slightly before the engine itself is 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 eng in e coolant. Consult th e local
authorities or reclamation facilit y.

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 environment.

4TNV98 & 4TNE98 (for D25G) Only

Replace the fuel filt er at specif ied 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 filter wrench, turning
it to the left (Figure 5-14, ( 1) ). When r em ov ing
the fuel filter, carefully hold it t o pr ev ent t he fuel
from spilling. W ipe up all spilled fuel.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 55

Figure 5-14

4. Clean the filter mount ing 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-tighten it only until it com es

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 specif ied 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) ).

4. Place an approv ed container under fuel filter.

5. Carefully open the drain 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 (Fi gu re 5- 15a, (2)) by turning it to
the left (Figure 5-15a, (3) ).

8. Check the conditi on of t he drain plug O-ring
(Figure 5-15a, (4) ). Replace the O-ring if

damaged.

9. Set the drain plug aside f or r einstallation.

Figure 5-14a

Figure 5-15

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance

56

10. Remove the fuel filt er sensor assem bly (Figure
5-15, (5)) by turning it to the left (Figure 5-15,
(3)).

11. Carefully remove the in-line fuel filter (Figu re 5­15, (7)) from the output nipple (Figure 5-15, (8))

that goes to the fuel injec tion pump.

12. Dispose of the fuel, fuel filters and O-ring (if
replaced) proper ly. Follow the guidelines of the
EPA or other government agency.

13. Carefully install the output nipple (Figure 5- 15,
(8)).

14. Carefully i nstall the fuel filter sensor assembl y
(Figure 5-15, (5) ) in the new f uel filter using the
new O-ring suppli ed 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 gu re 5- 15, (1)) on the

new fuel filter (Fig ure 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 ( Figure 5­15, (10)) and appl y 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 (Figure 5-14, (4)) until it
contacts the mounting surfac e. Tighten 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 Priming 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 an ce (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 component.

Failure to compl y will result in death or serious
injury.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 57

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 eng in e coolant. Consult th e local
authorities or reclamation facilit y.

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 environment.

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 coll ect 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 Dr ain 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 t he
senso r wi r e (Figure 5-15, ( 7) ) from the cup
before rem ovi ng the cup.

5. Carefully hol d the cup to pr ev ent fuel from
spilling. If you spill any fuel, clean up the spill
completely.

6. Remove the float ring (F ig ure 5-15, (8)) from the
cup. Pour the contami nants into the container
and dispose of it proper ly.

7. Clean the element (Fig ure 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- ring in the bracket.

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 the cup to the bracket by tightening t he

retaining ring to t he ri ght (Fi gure 5-15, (6)) to a
torque of 11-15 ft·lb (15-20 N·m; 1.5-2.0kgf·m).

12. Close the drain cock. Reconnect the sensor

wire if equipped.

13. Open the fuel cock (Figu re 5- 15, (3)).

14. Prime the fuel system. See Priming the Fuel

System on page 15.

15. Check for leaks.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance

58

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 spu rt 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 cool ant. Hot engine coolant may spl ash
and burn y ou.

Failure to comply could result in death or
serious in jur y .

CAUTION

COOLANT HAZARD!

Wear eye protection and rubber gloves when
you handle long life or extended life engine
coolant. If contact wit h 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

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 eng in e coolant. Consult th e local
authorities or reclamation facilit y.

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 environment.

Engine coolant contami nated with rust or scale
reduces the cooli ng eff ect. Ev en when ext ended life
engine coolant is properly mixed, the engine
coolant gets contaminated as its ingredients
deteriorat e. Dr ain, flush and refill the cooling
system with new coolant ev er y 1000 hour s or once
a year, whichever comes first.

1. Allow engine and coolant to cool.

2. Remove the radiat or cap (Fig ure 5-16, (1)).

3. Remove the drain plug or open the drain cock
(Figure 5-16, (2) ) at t he lower portion of the

radiator and dr ain the engine coolant.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 59

Figure 5-16

4. Drain the coolant from the engine block.

• On models not equipped with an oil cooler,
remove the coolant drain 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 t he cylinder
block drain plug or r ec onnec t the coolant hose at
the oil cooler.

6. Fill radi ator 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 timing for opening and closing the valves.
Improper adjustment will cause the engine t o run
noisily, resulting in poor engine perform anc e and
engine damage. See I ntak e/Ex haust Valve and
Guide on page 67.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance

60

Every 1500 Hours of Operation

Perform the following maintenance every 1500
hours of operation.

• Inspect, Clean and Test F uel Injectors

• Inspect Crankcase Br eather System

Inspect, Cl ean 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 indust rial engine
dealer or distributor repair the damage.

Failure to comply could result in death or
serious in jur y .

Proper operation of the fuel injectors is requir ed to
obtain the optimum injec tion pattern for full engine
perform anc e. The EPA / ARB requires that the fuel
injectors are inspected, cleaned and tested every
1500 hours. See Testing of F uel Injectors on page

164.
This procedure is considered normal mai ntenance

and is performed at the owner’s expense. This
procedure is not cov er ed by the Yanmar Limited
Warranty.

Inspect Crankcase Breather System

Proper operation of the crankcase breather system
is required t o mai ntain the emission requirements of
the engine. The EPA / ARB requires that the
crankcase breather sy stem is inspected every 1500
hours.

There are three diff er ent cr ank c ase 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 that has a spring-backed
diaphragm ( Fi gu re 5- 19, (1)) in the valve cover
(Figure 5-19, (2) ) . When the crankcase pressure
reaches a predeterm ined value, the diaphragm
opens a passage that allows crankcase fumes to be
routed to the intake m anifold.

To inspect t he diaphr agm and spring (Figure 5-19,

(3)):

1. Remove the bolts retaining the diaphragm cover
(Figure 5-19, (4) ).

Figure 5-19

2. Remove the diaphragm c ov er, spring, diaphragm
plate (Fig ure 5-19, (5)) and diaphragm.

3. Inspect the diaphragm for tears. Inspect t he

spring for di stor tion. Replace components if
necessary.

4. Reinstall the diaphr agm , diaphragm plate, spring
and diaphragm cover. Tighten the diaphragm
bolts to specified torque.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance 61

Failure of the diaphr agm and / or spring will cause
the loss of pressure contr ol and allow an excessive
amount of crankcase fumes to be routed 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 Fu el Hoses and Engi ne
Coolant Hoses

CAUTION

Regularly check the fuel system and engine coolant
system hoses. If they ar e crack ed or degraded,
replace them. Replace the hoses at least every two
years.

Lap the Intake and Exhaust Valves

Adjustment is necessary to maintain proper contact
of the valves and seats. See Inspect ion of Intake
and Exhaust Valves on page 98.

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 eng in e coolant. Consult th e local
authorities or reclamation facilit y.

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 environment.

4TNV98 & 4TNE98 Diesel Engine Section 2. Periodic Maintenance

62

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
accidentall y start 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 lon g hair,
and keep your hands, other body parts and
clothing away from moving/rotating parts.

Failure to comply could result in death or
serious in jur y ..

WARNING

FUME / BURN HAZARD!

Always read and follow safety related
precautions found on containers of hazardous
substances li ke parts cleaners, pri mers, sealants
and sealant remo vers.

Failure to comply could result in death or
serious in jur y .

CAUTION

FLYING OBJECT HAZARD!

ALWAYS wear eye protect ion when servicing the
engine and when using compressed air or high­pressure water. Du st, flying debris, compressed
air, pressurized w ater or steam may injure your
eyes.

Failure to comply may result in minor or
moderate injury.

Section 3. Engine 63

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.

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

CAUTION

Any part whi ch is 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 meet s the service standard limit.

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
appropriat e method. It is important th at all parts
are returned to the same position during the
reassembly pro cess.

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 64

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
appropriat e method .

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
constant up- a nd-down motion.

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 65

Introduction

This section of t he Servic e M anual describes
servicing of t he engine.

Cylinder Head Specifications

Adjustment Specifications

Model Valve Clearance

4TNV98

4TNE98

Cylinder Head

4TNV98 Engine

Inspection Item Standard Limit

0.006 - 0.010 in.

(0.15 - 0.25 mm)

0.006 - 0.010 in.

(0.15 - 0.25 mm)

Valve Bridge Clearance

(4-Valve Head Only)

0

-

Reference

Page

Combustion Surf ac e Distor tion (Flatness)

Valve Recession

Valve Seat
(4-Valve)

4TNE98 Engine

Combustion Surf ac e Distor tion (Flatness)

Valve Sink

Valve Seat Angle

4TNV98
(4-Valve Head)

Seat Angle

Seat Correcti on Angle 40°, 150° -

Inspection Item Standard Limit

0.0020 in.

(0.05 mm) or less

0.0142 - 0.0220 in.
Intake
Exhaust

Intake 120° -

Exhaust 90° -

Intake

Exhaust
Intake 120° -

Exhaust 90° -

(0.36 - 0.56 mm)

0.0138 - 0.0217 in.

(0.35 - 0.55 mm)

0.0020 in.

(0.05 mm) or less

0.020 - 0.028 in.
(0.5 - 0.7 mm)

0.024 - 0.032 in.
(0.6 - 0.8 mm)

0.0059 in.

(0.15 mm)

0.0315 in.
(0.8 mm)

0.0315 in.
(0.8 mm)

0.0059 in.

(0.15 mm)

0.039 in.

(1.0 mm)

0.043 in.

(1.1 mm)

See Valve

Recession

Page 95

and 98.

See Valve

Face and

Valve Seat

Page 96

and 99.

Reference

Page

See

Inspection

of Cylinder

Head on

page 94.

See

Inspection

of Intake

and

Exhaust

Valves on

page 95.

on

on

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 66

Intake / Exhaust Valve and Guide Cont

4TNV98 Engine

Inspection Item Standard Limit

Guide I nsid e Diameter

Intake

4TNV98
(4-Valve Head)

Exhaust

Valve Guide Projection From Cylinder Head

Valve Guide Installation Method Cold-fitted -

Valve Stem Seal Projection From Cylinder Head

Valve Stem Outside
Diameter

Oil C learanc e

Guide I nsid e Diameter
Valve Stem Outside

Diameter
Valve Stem Bend

0.2756 - 0.2762 in.

(7.000 - 7.015 mm)

0.2734 - 0.2740 in.

(6.945 - 6.960 mm)

0.0016 - 0.0028 in.

(0.040 - 0.070 mm)

0.2756 - 0.2762 in.

(7.000 - 7.015 mm)

0.2732 - 0.2738 in.

(6.940 - 6.955 mm)

0.0018 - 0.0030 in.

(0.045 - 0.075 mm)

0.3819 - 0.3937 in.
(9.70 - 1 0 .0 0 mm)

0.460 - 0.472 in.
(11.7 - 12.0 mm)

0.2787 in.

(7.08 mm)

0.2717 in.

(6.90 mm)

0.0067 in.

(0.17 mm)

0.2787 in.

(7.08 mm)

0.2717 in.

(6.90 mm)

0.0067 in.

(0.17 mm)

-

-

Reference

Page

See

Inspection of

Valve

Guides on

page 94.

See

Reassembly

of Valve

Guides on

page 97

and 103.

See

Reassembly

of Intake and

Exhaust

Va lves on

page 98.

4TNE98 Engine

Inspection Item Standard Limit

Guide I nsid e Diameter

Intake Valve

Exhaust Valve

Valve Guide Projection From Cylinder Head

Valve Stem Seal Projection From Cylinder Head

Valve Stem Outside Diam eter

Oil C learanc e

Guide I nsid e Diameter

Valve Stem Outside Diam eter

Oil C learanc e

0.3156 - 0.3161 in.

(8.015 – 8.030 mm)

0.3136 - 0.3142 in.

(7.965 – 7.980 mm)

0.0014 - 0.0026 in.

(0.035 - 0.065 mm)

0.3156 - 0.3161 in.

(8.015 – 8.030 mm)

0.3136 - 0.3138 in.

(7.965 – 7.970 mm)

0.0018 - 0.0030 in.

(0.045 - 0.075 mm)

0.58 - 0.60 in.

(14.7 – 15.0 mm)

0.66 - 0.70 in.

(16.7 – 17.0 mm)

0.3189 in.

(8.10 mm)

0.3110 in.

(7.90 mm)

0.0071 in.

(0.18 mm)

0.3189 in.

(8.10 mm)

0.3110 in.

(7.90 mm)

0.0071 in.

(0.18 mm)

-

-

Reference

Page

See

Inspection of

Intake and

Exhaust

Va lves on

page 95.

See

Assembly of

Valve

Guides on

page 98.

See

Assembly of

Valve

Guides on

page 98.

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 67

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)

Rocker Arm and Shaft

Inspection Item St andard Limit

Arm Shaft Hole Diam eter

Shaft Outside Diameter

Oil Clearance

0.7283 - 0.7291 in.

(18.500 - 18.520 mm )

0.7272 - 0.7280 in.

(18.470 - 18.490 mm )

0.0004 - 0.0020 in.
(0.010 - 0.050 mm)

0.7311 in.

(18.57 mm)

0.7260 in.

(18.44 mm)

0.0051 in.

(0.13 mm)

Valve Spring

Inspection Item Mode l Sta ndard Limit

Free Length

Squareness

4TNV98 (4-Valve Head)

4TNE98

4TNV98 (4-Valve Head) -

4TNE98 -

1.5630 in.

(39.7 mm)

1.87 in.

(47.5 mm)

1.5433 in.

(39.2 mm)

-

0.0551 in.
(1.4 mm)

0.05 in.

(1.2 mm)

Camshaft and Timing Gear Train Specifications

Camshaft

Inspection Item St andard Limit

See Push
Rod Bend

on page 93.

Reference

Page

See

Inspection of

Rocker Arm

Assembly on

page 93 and

94.

Reference

Page

See

Inspection of

Valve

Springs on

page 97 and

101.

Reference

Page

End Play

Bend (1/2 the dial gauge reading)

4TNV98

Cam Lobe Height

4TNE98

Shaft Outside Diameter / Bearing Inside Diameter

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 68

0.0020 - 0.0079 in.

1.7087 - 1.7165 in.

(43.400 - 43.600 mm )

1.6707 - 1.6758 in.

(42.435– 42.565 mm)

(0.05 - 0.20 mm)

0 - 0.0008 in.

(0 - 0.02 mm)

0.0118 in.

(0.030 mm)

0.0020 in.

(0.05 mm)

1.6988 in.

(43.150 mm)

1.6608 in.

(42.185 mm)

See

Removal of

Camshaft on

page 114.

See
Inspection of
Camshaft on

page 125.

(Camshaft Cont.)

Gear End

Inspection Item Standard Limit

Bushing Inside Diam eter

Camshaft Outside Diamet er

1.9681 - 1.9707 in.

(49.990 - 50.055 mm )

1.9655 - 1.9665 in.

(49.925 - 49.950 mm )

1.9736 in.

(50.130 mm)

1.9642 in.

(49.890 mm)

Reference

Page

Oil Clearance

Bushing Inside Diam eter

Intermediate

Flywheel End

Camshaft Outside Diamet er

Oil Clearance

Bushing Inside Diam eter

Camshaft Outside Diamet er

Oil Clearance

Idler Gear Shaft and Bushing

Inspection Item Standard Limit

Shaft Outside Diameter

Bushing Inside Diam eter

Oil Clearance

Timing Gear Backlash

Inspection Item Standard Limit

0.0016 - 0.0051 in.

(0.040 - 0.130 mm)

1.9685 - 1.9695 in.

(50.000 - 50.025 mm )

1.9650 - 1.9659 in.

(49.910 - 49.935 mm )

0.0026 - 0.0045 in.

(0.065 - 0.115 mm)

1.9685 - 1.9695 in.

(50.000 - 50.025 mm )

1.9655 - 1.9665 in.

(49.925 - 49.950 mm )

0.0020 - 0.0039 in.

(0.050 - 0.100 mm)

1.8091 - 1.8100 in.

(45.950 - 45.975 mm )

1.8110 - 4.8120 in.

(46.000 - 46.025 mm )

0.0010 - 0.0030 in.

(0.025 - 0.075 mm)

0.0094 in.

(0.240 mm)

1.9724 in.

(50.100 mm)

1.9636 in.

(49.875 mm)

0.0089 in.

(0.225 mm)

1.9724 in.

(50.100 mm)

1.9642 in.

(49.890 mm)

0.0083 in.

(0.210 mm)

1.8071 in.

(45.900 mm)

1.8140 in.

(46.075 mm)

0.0069 in.

(0.175 mm)

See
Inspection of
Camshaft on

page 125.

Reference

Page

See
Inspection of

Idler Gear

and Shaft on

page 126.

Reference

Page

Crank Gear, Cam Gear, Idler Gear, Fuel Injection
Pump Gear and PTO Gear

Lubricating Oil Pump Gear

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 69

0.0031 - 0.0055 in.
(0.08 - 0.14 mm)

0.0035 - 0.0059 in.
(0.09 - 0.15 mm)

0.0063 in.

(0.16 mm)

0.0067 in.

(0.17 mm)

See

Checking
Timing Gear
Backlash on

page 112.

Crankshaft and Piston Specifications

Crankshaft

NOTE : Check appropri ate parts catalog for various

sizes of replacem ent main bearing inserts.

Inspection Item Standard Limit

Bend (1/2 the dial gauge reading) -

Journal Outside
Diameter

Bearing Inside

Connecting Rod Journals

Main Bearing Jour nal

Diameter
Bearing Insert

Thickness
Oil Clearance
Journal Outside

Diameter
Bearing Inside

Diameter
Bearing Insert

Thickness
Oil Clearance

Thrust Bearing

Inspection Item Standard Limit

4TNV98

Crankshaft End Play

4TNE98

2.2816 - 2.2820 in.

(57.952 - 57.962 mm )

2.2835 - 2.2845 in.

(58.000 - 58.026 mm )

0.0587 - 0.0591 in.

(1.492 - 1.500 mm)

0.0015 - 0.0029 in.

(0.038 - 0.074 mm)

2.5572 - 2.5576 in.

(64.952 - 64.962 mm )

2.5590 - 2.5598 in.

(65.000 - 65.020 mm )

0.0785 - 0.0791 in.

(1.995 - 2.010 mm)

0.0015 - 0.0027 in.

(0.038 - 0.068 mm)

0.0051 - 0.0091 in.
(0.13 - 0.23 mm)

0.0043 - 0.0083 in.
(0.11 - 0.21 mm)

0.0008 in.

(0.02 mm)

2.2796 in.

(57.902 mm)

-

0.0059 in.

(0.150 mm)

2.5552 in.

(64.902 mm)

-

-

0.0059 in.

(0.150 mm)

0.0110 in.

(0.28 mm)

0.0110 in.

(0.28 mm)

Reference

Page

See

Inspection of

Crankshaft

on Page

124.

See

Inspection of

Crankshaft

on page

124.

Reference

Page

See

Removal of

Crankshaft

on Page

1 18.

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 70

Piston

Inspection Item Standard Limit

Piston Outside Diameter
(Measure at 90° to the Piston Pin.)

Piston Diameter Measure Location(Upward
From the Bottom of the Pi ston.)

Hole Inside Diamet er

Piston Pin

Pin Outside Diameter

Oil Clearance

Piston Ring

3.8555 - 3.8567 in.

(97.930 - 97.960 mm )

0.8661 in.
(22 mm)

1.1811 - 1.1815 in.

(30.000 - 30.009 mm )

1.1807 - 1.1811 in.

(29.989 - 30.000 mm )

0.0000 - 0.0008 in.
(0.000 - 0.020 mm)

3.8541 in.

(97.895 mm)

-

1.1826 in.

(30.039 mm)

1.1795 in.

(29.959 mm)

0.0031 in.

(0.080 mm)

Reference

Page

See

Inspection of

Pistons,

Piston Rings

and Wrist

Pin on page

122.
See

Inspection of

Pistons,

Piston Rings

and Wrist

Pin on page

122.

Model Inspection Item Standard Limit

0.0803 - 0.0811 in.

(2.040 - 2.060 mm)

0.0764 - 0.0772 in.

(1.940 - 1.960 mm)

0.0031 - 0.0047 in.

(0.080 - 0.120 mm)

0.0098 - 0.0177 in.

(0.250 - 0.450 mm)

0.0819 - 0.0825 in.

(2.080 - 2.095 mm)

0.0776 - 0.0783 in.

(1.970 - 1.990 mm)

0.0035 - 0.0049 in.

(0.090 - 0.125 mm)

0.0177 - 0.0256 in.

(0.450 - 0.650 mm)

0.1187 - 0.1193 in.

(3.015 - 3.030 mm)

0.1169 - 0.1177 in.

(2.970 - 2.990 mm)

0.0010 - 0.0024 in.

(0.025 - 0.060 mm)

0.0098 - 0.0177 in.

(0.250 - 0.450 mm)

-

0.0756 in.

(1.920 mm)

-

0.0213 in.

(0.540 mm)

0.0864 in.

(2.195 mm)

0.0768 in.

(1.950 mm)

0.0096 in.

(0.245 mm)

0.0287 in.

(0.730 mm)

0.1232 in.

(3.130 mm)

0.1161 in.

(2.950 mm)

0.0071 in.

(0.180 mm)

0.0217 in.

(0.550 mm)

4TNV98

Ring Groove Wi dth

Ring Width

Top Ring

Side Clearance

End Gap

Ring Groove Wi dth

Ring Width

Second Ring

Side Clearance

End Gap

Ring Groove Wi dth

Ring Width

Oil Ring

Side Clearance

End Gap

Reference

Inspection of

Pistons,

Piston Rings

and Wrist

Pin on page

Page

See

122.

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 71

Connecting Rod

Connecting Rod Small End

Inspection Item Standard Limit Reference Page

Wrist Pin Bushing Inside Diameter

Wrist Pin Outside Diameter

Oil Clearance

Connecting Rod Big End

Inspection Item Standard Limit

4TNV98
Side Clearance
(Thrust Clear anc e)

4TNE98 0.0051 - 0.0091 in. -

See Special Torque Chart on page 69 for other specificat ions.

1.1821 - 1.1826 in.

(30.025 - 30.038 mm )

1.1806 - 1.1811 in.

(29.987 - 30.000 mm )

0.0010 - 0.0020 in.
(0.025 - 0.51 mm)

0.0079 - 0.0157 in.

(0.20 - 0.40 mm)

Tappet

1.1838 in.

(30.068 mm)

1.1795 in.

(29.959 mm)

0.0043 in.

(0.109 mm)

-

See Inspection of

Connecting Rod on

page 124.

Reference

Page

See Inspection of

Connecting Rod on

page 124.

Inspection Item Standard Limit Reference Page

Tappet Bore (Bl oc k ) Insi de Diameter

Tappet Stem Outside Diameter

Oil Clearance

0.4724 - 0.4731 in.

(12.000 - 12.018 mm )

0.4715 - 0.4720 in.

(11.975 - 11.990 mm)

0.0004 - 0.0017 in.

(0.010 - 0.043 mm)

0.4739 in.

(12.038 mm)

0.4707 in.

(11.955 mm)

0.0033 in.

(0.083 mm)

See Inspection of

Tappets on page

124.

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 72

Cylinder Block Specifications

Cylinder Block

Inspection Item Standard Limit

Cylinder Inside Diam eter

Roundness

Cylinder Bore

Taper

Special Torqu e Char t

Torque for Bolts and Nuts

Component

Thread Diameter

and Pitc h

3.8583 - 3.8594 in.

(98.000 - 98.030 mm )

0.0004 in. (0.01 mm)
or less

Torque

3.8634 in.

(98.130 mm)

0.0012 in.

(0.03 mm)

Lubricating Oil

(Thread Portion

and Seat Surface)

Reference

Page

See

Inspection

of Cylinder

Block on

page 121.

Application

Cylinder Head Bolt M11 x 1.25 mm

Connecting Rod Bolt M10 x 1.0 mm

Flywheel Bolt M14 x 1.5 mm

76 - 83 ft·lb

(103.1 - 112.9 N·m;

10.5 - 11.5 kgf·m)
40 - 43 ft·lb

(53.9 - 58.8 N·m;

5.5 - 6.0 kgf·m)
137 - 152 ft·lb

(186.2 - 205.8 N·m;

19 - 21 kgf·m)

Applied

Applied

Applied

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 73

(Torque for Bolts and Nuts Cont.)

Component

Main Bearing Cap Bolt M11 x 1.25 mm

Crankshaft Pulley Bolt M14 x 1.5 mm

Thread Diameter and

Pitch

Torque

80 - 87 ft·lb

(108.1 - 117.9 N·m;

11.0 - 12.0 kgf·m)
80 - 94 ft·lb

(107.9 - 127.5 N·m;

11.0 - 13.0 kgf·m)

Lubricating Oil

Application

(Thread Portion

and Seat Surface)

Applied

Applied

Fuel Injector
Bolt

Fuel Pump
Drive Gear
Nut

High-Pressure
Fuel Lines Bolt

Fuel Return
Line Joint Bolt

See Tightening Torques for Standard Bolts and Nuts on page 23 for standard hardware torque values.

4TNV98 M8 x 1.25 mm

4TNV98 M18 x 1.5 mm

4TNV98 M12 x 1.5 mm

4TNV98 M6 x 1.0 mm

17 - 21 ft·lb

(22.6 - 28.4 N·m;

2.3 - 2.9 kgf·m)
83 - 90 ft·lb

(113 - 123 N·m;

11.5 - 12.5 kgf·m)
174 - 217 in·lb

(19.6 - 24.5 N·m;

2.0 - 2.5 kgf·m)
70 - 86 in·lb

(7.8 - 9.8 N·m;

0.8 - 1.0 kgf·m)

Not Applied

Not Applied

Not Applied

Not Applied

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 74

Special Service Tools

No. Tool Name Applicable Model and Tool Size Illustration

Model L1 L2 d1 d2

Valve Guide
Tool (For

1

Removing
Valve Guide)

Valve Guide
Tool (For

2

Installing
Valve Guide)

4TNV98

4TNE98
Locally Manufac tured

Model L1 L2 d1 d2

4TNV98

4TNE98

0.787 in.
(20 mm)

0.787 in.
(20 mm)

0.276 in.
(7 mm)

0.591 in.

(15 mm)

2.953 in.
(75 mm)

2.953 in.
(75 mm)

2.362 in.
(60 mm)

2.559 in.
(65 mm)

0.256 in.

(6.5 mm)

0.295 in.

(7.5 mm)

0.512 in.
(13 mm)

0.551 in.
(14 mm)

0.394 in.
(10 mm)

0.433 in.
(1 1 mm)

0.630 in.
(16 mm)

0.787 in.
(20 mm)

Locally Manufac tured

Connecting
Rod Bushing
Replacer
(For
Removal/

4

Installation of
Connecting
Rod
Bushing)

Valve S pring
Compressor
(For

5

Removal/
Installation of
Valve S pring)

Stem Seal
Installer
(for Installing

6

Valve Stem
Seal)

L1 L2 d1 d2

0.787 in.
(20 mm)

Locally Manufac tured

Model d1 d2 d3 L1 L2 L3

4TNV98

4TNE98

0.598
in.

(15.2

mm)

0.638
in.

(16.2

mm)

3.937 in.

(100 mm)

Yanmar Part No.

129100-92630

0.827
in.

(21

mm)

0.866
in.

(22

mm)

0.472
in.

(12

mm)

0.531
in.

(13.5

mm)

1.181 in.
(30 mm)

0.465
in.

(11.8

mm)

0.669
in.

(17.0

mm)

1.299 in.
(33 mm)

2.559
in.

(65

mm)

2.560
in.

(65

mm)

0.157
in.

(4

mm)

0.157
in.

(4

mm)

Locally Manufac tured

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 75

(Special Service Tools Cont.)

No. Tool Name Applicable Model and Tool Size Illustration

Filter Wrench
(For Removal
/ Installation

7

Available Locally
of Engine Oil
Filter)

Camshaft
Bushing Tool
(For

8

Extracting
Camshaft
Bushing)

L1 L2 d1 d2

0.709 in.
(18 mm)

Allowance

: d1

2.756 in.
(70 mm)

- 0.3

- 0.6

1.968 in.
(50 mm)

, d2

- 0.3

- 0.6

2.087 in.

(553 mm)

Locally Manufac tured

Yanmar Part No. Cylinder Bor e
Flex-Hone
(For

9

Preparation
of Cylinder
Walls)

129400-92440

3.504 - 3.976 in.
(89 - 101 mm)

Piston Ring
Compressor

10

(For Installing
Piston)

Piston Ring
Expander
(For Removal

11

/ Installation
of Piston
Ring)

Crankshaft

12

Pulley
Installing Tool

Yanmar Part No. 95550-002476

The Piston Insertion Tool is Applicable for 2.362 - 4.921 in.

(60 - 125 mm) Diameter Pistons

Available Locally

Locally Manufac tured

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 76

Measuring Instruments

No. Instrument Name Application Illustration

1 Dial Indicator Locall y Available Measure shaft bend and end play

Measurements of narr ow or deep

2 Test Indicator Locally Available

3 Magnetic Stand Locally Available

4 Micrometer Locally Available

Cylinder Bore

5

Gauge

6 Calipers Locally Available

Depth

7

Micrometer

8 Square Locally Available

Loca lly Availab le

Locally Available For measuring of valve recession

portions that c annot be measured by dial
gauge

For holding the dial gauge when
measuring

For measuring t he outside diam eters of
crankshaft, pistons, piston pins, etc.

For measuring t he insi de diam eters of
cylinder li ners, bearing bores, etc.

For measuring outside diameters, depth,
thickness and width

For measuring valve spring inclination
and straightness of parts

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 77

No. Instrument Name Application Illustration

9 V-Block Locally Available For measuri ng shaft bend

10 Torque Wrench Locally Available

11 Feeler Gauge Locally Available

12 Battery Coolant Tester

For tightening nuts and bolts to t he
specified t orque

For measuring piston ring gaps,
piston ring cl ear anc e, and valve
adjustment clear anc e

For checking conc entration of
antifreez e and the bat tery electrolyte
charge status

13 Digital Thermometer For measuring temperatures

For measuring rev olution by
contacting the revolving shaft

For measuring rev olution by sensing
the reflecting mark on the outer
periphery of the r ev olv ing shaft

This measures the rev olution
regardless of t he c enter or periphery
of the revolving object

14 Tachometer

Contact Type

Photoelectric
Type

Fuel High
Pressure Pipe
Clamp Type

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 78

No. Instrument Name Application Illustration

15 Circuit Tester

Compression Gauge Kit

16

New Comperssion Test
Adaptor

For measuring resistance, voltage and
continuity of electrical circuits

For measuring compression
pressureGauge Set Par t No. TOL­97190080

Adapter for direct injection 2-valve
cylinder headAdapt er Part No. 119802­92950

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 79

Cylinder Head

Cylinder Head Components

4TNV98 Engine

Figure 6-36

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 80

(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) Fu el Injector R etai n er Bolt.
(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) Int ak e Valve.
(21) Exhaust Valve. (22) Cylinder Head Gasket. (23) Fuel Injector Noz zl e Pr otect or.
(24) Fuel Injector Noz zl e S eat . (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 81

Disassembly of 4-Valve Cylinder Head

Prepare a clean, flat working surface on a
workbench large enough to acc om modate the
cylinder head assembly. 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 Cooling
System with New Coolant on page 163.

CAUTION

Identify all parts and their location using an
appropriat e method. It is important th at all parts
are returned to the same position during the
reassembly pro cess.

2. Remove the high pressure fuel 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 cyli nder head.

4. Disconnect t he hoses (Figure 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 wi r e from the intake air
heater (F igure 6- 38, (12)).

7. Remove the intake manifold bolts (Figure 6-38,
(11)). Remove the intake manifold (Figure 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 (Figure 6-38,
(6)) with the turbocharger at tached. Discard the
exhaust manifold gasket. (Figure 6-38, ( 5)).

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 82

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 injection lines and

valve cover gromm ets must be remov ed pri or 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 scr ewdriver (Figure 6-39) to
remove the fuel injection line grommets (Figure 6­40, (1)) from the valve cover (Figure 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 scr ewdriver.

Figure 6-39

3. Remove the valve cover nuts (Figu re 6- 40, (4)).

4. Remove the O-ring (Fig ure 6-40, (5)) on each

valve cover nut.

Figure 6-40

5. Remove the valve cover (Figure 6-40, (3)).
Discard the valve cover gasket (Figure 6-40, (6) ) .

6. Inspect and clean the c rankcase breather

assembly. See Inspect Crankcase Breather
System on page 61.

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 83

Removal of Rocker Arm Assemb ly

1. Remove the fuel injec tors from the cylinder head.

See Removal of Fuel Injectors on page 163.

2. Remove the bolts (Figure 6-41, (1)) that retain the
rocker arm shaft supports to the cyl inder head.

3. Remove the rocker arm and shaft assembly from
the cylinder head.

NOTE : Identify the push rods and v alve bridges so
they can be installed in their original locati ons.

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 reinstalled in
their original locations.

Figure 6-41

Disassembly of Rocker Arm Assembly
NOTE : Identify the roc k er arm s so they can be

reinstalled with the original matching v alv e and
pushrod.

1. Remove the rocker arm shaft ali gnm ent studs
(Figure 6-42, (5) ) from the r oc k er arm shaft
supports (Fig ure 6-42, (6)).

2. Slide the supports, wave washers (Figure 6-42,
(7)), rocker arm s (Figure 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 surface.

Figure 6-42

NOTE : Figur e 6 -42 shows components for one

cylinder. Components for all remaini ng cylinders are
assembled in the same or der.

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 84

Removal of Cylinder Head

1. Loosen the cylinder head bolts following the
sequence shown in (Fi gu re 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 to

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 with

the combustion si de down.

2. Using the valve spring compressor tool, compress
one of the valve springs (Fi gu re 6- 45) .

Figure 6-45

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 85

3. Remove the valve keepers (F ig ure 6-46, (1)).

4. Slowly release t he tension on the valve spring.

5. Remove the spring retai ner (Fig ure 6-46, (2)),
valve spring (Fig ure 6-46, (3)).

Figure 6-46

6. Repeat the procedur e wi th all the remaining

valves.

NOTE : If the valves are to be reused, i dentify them
so they can be installed in their ori ginal location.

7. Remove the inject or nozzle protectors (Figu re 6­46, (6)) and the seats (Figure 6-46, (7)).

8. Turn the cylinder head so the exhaust port side

faces down. Remov e the intake and exhaust
valves (Figure 6-46, (5)) from the cylinder head.

9. Remove the valve stem seals (F ig ure 6-46, (4)).

Removal of Valve Guides
NOTE : Removal of the valve guides should be

postponed until inspection and measurement
procedures hav e been performed. See Inspection of
Valve Guides on page 94.

1. Using a drift pin and hammer, drive the valve
guides (Fi gu re 6- 47, (1)) out of the cylinder head.

Figure 6-47

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 86

4TNE98 Engine

Figure 6-1

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 87

(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 Nu t

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 88

Disassembly of Cylinder Head

Prepare a clean, flat working surface on a
workbench large enough to accommodate the
cylinder head assem bl y. Discard all gaskets, O-rings
and seals.

CAUTION

Identify all parts and their location using an
appropriat e method. It is important th at all parts
are returned to the same position during the
assembly pro cess.

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 harness (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 (Figu re 6- 4, (1)).

2. Check the conditi on of t he O- ri ng (Figure 6-4, (2))

on each valve cover nut. Replace the O-ring if
necessary.

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 89

Figure 6-4

3. Remove the valve cover (Figure 6-4, (3)). Discard
the valve cover gasket (F ig ure 6-4, (4)).

Removal of Rocker Arm Assemb ly

1. Remove the bolt (Figu re 6- 6, (1) ) and loc ki ng

nuts (Figure 6-6, (2)) that retain the rocker arm
support brackets to t he cylinder head.

2. Lift the rocker arm assembl y from the c yli nder
head.

3. Lift the push rods from the cylinder head.

4. Number the push rods so that they ar e r einstal led

with the same valve tappet and roc k er arm.

Figure 6-6

Disassembly of Rocker Arm Assembly

1. Remove the rocker arm shaft ali gnm ent screw
(Figure 6-7, (1) ) fr om t he 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 (Figure 6-7, (2)) out of

the rocker arm support brac k ets (F ig ure 6-7, (4)),
springs (Figure 6-7, (5)), and rocker arms (Figure

-7, (6)).

NOTE : The rocker arm shaft fits tightly in the roc k er

arm support brackets. Cl am p the support br ac k et in
a padded vise and twist the roc k er arm shaft to
remove. Reverse this process when you reinstall t he
rocker arm shaft into the support br ac k ets.

NOTE : Mark the rocker arms so they can be
reinstalled with the original matching v alv e and
pushrod.

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 90

Figure 6-7

4. .If necessary, remove the valve adjusting screw
(Figure 6-7, (7) ) and l oc k nut (F igure 6- 7, (8))

from the rocker arms.

Removal of Cylinder Head

1. Loosen the cylinder head bolts following the

sequence shown in (Fi gu re 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 with

the combustion si de down.

2. Using the valve spring compressor tool, compress
one of the valve springs (Fi gu re 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 91

4. Slowly release t he tension on the valve spring.

5. Remove the spring retai ner (Fig ure 6-11, (3)),

valve spring (Fig ure 6-11, (4)) and valve stem
seal (Figure 6-11, (5)).

Figure 6-11

6. Repeat this procedure until all the intake and

exhaust valv e springs and valve stem seals are
removed.

NOTE : If you are going to reinstall the valves in the
cylinder head, mark them so they can be installed in
their original location.

7. Turn the cylinder head so the exhaust port side
faces down. Remov e 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 (Fi gu re 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 li ke parts cleaners, pri mers, sealants
and sealant remo vers.

Failure to comply could result in death or
serious in jur y .

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 92

Thoroughly cl ean all c om ponents using a non­metallic brush and an appropri ate solvent. Each part
must be free of carbon, m etal fili ngs and other
debris.

Inspection of Cylinder Head
Components

Visually inspect the 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 whi ch is 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 meet s the service standard limit.

Inspection of Push Rod s

Push Rod Bend

1. Place the push rods on a fl at inspection block or

layout bed.

2. Roll the push rods until a gap can be observed
between a portion of t he push rod and the surface
of the block or layout bed.

3. Use a feeler gauge to measure the gap ( Fi gure 6-

48). See Push Rod on page 68 for the servi c e limit.

Figure 6-48

Inspection of Rocker Arm Assembly

Rocker Arm Shaft Hole Diameter

1. Use a telescoping gauge and m ic r om eter to

determine if the inside diameter of all the rock er
arm support brackets and the rock er arms (Figure
6-49) are withi n the specified limits. See Rocker
Arm and Shaft on page 68 for the service limit .

2. Inspect the contact ar eas (F ig ure 6-49, (1)) for
excessiv e wear or damage.

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 93

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 eac h r ocker arm
location in two directions 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 the valve guides for distortions,
scoring or other dam age.

NOTE : Measure the valv e guides whil e they are
installed in cylinder head.

Use a telescoping gauge and micrometer to
measure the inside diameter 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 Distortion

Place the cylinder head fl at and inverted
(combustion side up) on the bench. Use a straight
edge and feeler gauge to m easure c yl 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 94

If distortion exc eeds t he service limit, resurface or
replace the cyli nder head. Remove only enough
material to mak e 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 the intake and exhaust valves.
Replace any valves that are obviously discolored,
heavily pitted or otherwise 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 I ntake/Ex haust Valve and Guide on
page 67 for the service limit.

Figure 6-53

Valve Stem Bend

Place the valv e stem on a fl at inspection block or
layout bed. Roll the valv e until a gap can be
observed between a port ion 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 to

perform this check .
Insert the valves into their original locations and

press them down until they ar e fully seated. Use a
depth micromet er (Figure 6-55) to measure the
difference between the c yl 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 is similar.

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 95

Figure 6-56

Valve Face and Valve Seat

Always check the cl earance 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 t he
limit, repl ac e the valv e and/or valve guide to bring
the clearance within the limit.

Roughness or burrs will cause poor seating of a
valve. Visually inspect the seating surfaces of each
valve and valve seat t o determine if lapping or
grinding is needed.

Visually inspect all valv es fac es and valve seats for
pitting, di st or tion, cracking, or evidenc e of
overheating. Usual ly the valves and valve seats can
be lapped or ground to r eturn them to serviceable
condition. S ev erely worn or damaged components
will requir e r eplac em ent.

Coat the valve seat with a thin coat of bluing
compound. Install the valv e and rotate to distribute
bluing onto the valv e face. The contact pattern
should be approximately centered on the valve 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 (F ig 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 lar ger. Once the seat location has
been corrected, grind and lap the seat angle (Figure
6-58, (1)) to specification. See Cylinder Head on
page 66 for specifications.

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 96

Grind the valve f ace and/or valve seat as necessary
to return them to servi c 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 thoroughl y wash all parts to remove all
grinding powder or com pound.

Inspection of Valve Springs

Inspect the valve springs. If damage or corrosi on is
seen, or if measurements exceed the specified limits,
replace the springs.

Fractures

Check for fractures on the inside and outside
portions of the springs. If the valve spring is
fractured, replace the valve spring.

Corrosion

Check for corr osi on of spri ng m aterial caused by
oxidation.

Squareness

Use a flat surface and a square t o c hec k each
spring for squarenes s (F igure 6-59). See Valve
Spring on page 68 for the service limit.

Figure 6-59

Free Length

Use a caliper to measure the length 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 the contact surface at both ends of
the valve bridge (F igure 6- 61, (2)) for excessive
wear or mushrooming.

Remove and inspect the seat (Figure 6-61, (1)).
Measure the diamet er of t he v alv e bri dge guide pin

bore in the valve bri dge and guide pin (Figure 6-61,
(3)). See Rocker Arm and Shaft on page 68 for the
ser vic e limit.

Figure 6-61

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 97

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 premature wear or damage.

Reassembly of Valve Guides

1. The valve guides are install ed 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 twenty minutes This will
cause the valve gui des to contract, making 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 (Fig ure 6-62,

(1)) in their proper positions.

4TNV98 Engine

4TNE98 Engine

Figure 6-62

3. Finish installi ng 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 (Fig ure 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)), i nstall a new v alv e stem seal on each of
the valve guides (F igure 6- 64, (3)).

Figure 6-64

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 98