ENGINE MECHANICAL (6VE1 3.5L) 6A-17
Engine Oil Consumption Excessive
Symptom Possible Cause Action
Oil leaking Oil pan drain plug loose Retighten or replace gasket
Crankcase fixing bolts loosened Retighten
Oil pan setting bolts loosened Retighten
Oil pan gasket broken Replace gasket
Front cover retaining bolts loose or
gasket broken Retighten or replace gasket
Head cover fixing bolts loose or
gasket broken Retighten or replace gasket
Oil filter adapter cracked Replace
Oil filter attachings bolt loose or
rubber gasket broken Retighten or replace oil filter
Oil cooler broken Replace
Crankshaft front or rear oil seal
defective Replace oil seal
Oil pressure unit loose or broken Retighten or replace
Blow–by gas hose broken Replace hose
Positive Crankcase Ventilation Valve
clogged Clean
Engine/Transmission coupling failed Replace oil seal
Oil leaking into combustion chambers
due to poor seal in valve system Valve stem oil seal defective Replace
Valve stem or valve guide worn Replace valve and valve guide
Oil leaking into combustion chambers
due to poor seal in cylinder parts Cylinders and pistons worn
excessively Replace cylinder body assembly and
pistons
Piston ring gaps incorrectly
positioned Correct
Piston rings set with wrong side up Correct
Piston ring sticking Replace cylinder body assembly and
pistons
Piston ring and ring groove worn Replace pistons and others
Return ports in oil rings clogged Clean piston and replace rings
Positive Crankcase Ventilation
System malfunctioning Positive Crankcase Ventilation Valve
clogged Clean
Others Improper oil viscosity Use oil of recommended S.A.E.
viscosity
Continuous high speed driving and/or
severe usage such as trailer towing Continuous high speed operation
and/or severe usage will normally
cause increased oil consumption
6A-18 ENGINE MECHANICAL (6VE1 3.5L)
Fuel Consumption Excessive
Symptom Possible Cause Action
Trouble in fuel system Mixture too rich or too lean due to
trouble in fuel injection system Refer to “Abnormal Combustion"
Fuel cut function does not work Refer to “Abnormal Combustion"
Trouble in ignition system Misfiring or abnormal combustion due
to trouble in ignition system Refer to “Hard Start" or “Abnormal
Combustion"
Others Engine idle speed too high Reset to Section 6E
Returning of accelerator control
sluggish Correct
Fuel system leakage Correct or replace
Clutch slipping Correct
Brake drag Correct
Selection of transmission gear
incorrect Caution operator of incorrect gear
selection
Lubrication Problems
Symptom Possible Cause Action
Oil pressure too low Wrong oil in use Replace with correct engine oil
Relief valve sticking Replace
Oil pump not operating properly Correct or replace
Oil pump strainer clogged Clean or replace strainer
Oil pump worn Replace
Oil pressure gauge defective Correct or replace
Crankshaft bearing or connecting rod
bearing worn Replace
Oil contamination Wrong oil in use Replace with correct engine oil
Oil filter clogged Replace oil filter
Cylinder head gasket damage Replace gasket
Burned gases leaking Replace piston and piston rings or
cylinder body assembly
Oil not reaching valve system Oil passage in cylinder head or
cylinder body clogged Clean or correct
6A-48 ENGINE MECHANICAL (6VE1 3.5L)
Rear Oil Seal
Removal
1. Remove transmission assembly.
See Transmission section in this manual.
2. Remove flywheel.
3. Remove rear oil seal using a seal remover.
NOTE: Take care not to damage the crankshaft or oil
seal retainer when removing oil seal.
Installation
1. Apply engine oil to oil seal lip and install oil seal
using 5884022860.
015RS017
2. Install flywheel.
Clean tapped holes in the crankshaft.
Remove oil on the crankshaft and flywheel
mounting surface.
Tighten fixing bolts to the specified torque.
NOTE: Do not reuse the bolts and do not apply oil o
r
thread lock to the bolts.
Torque: 54 N
m (5.5 kg
m/40 lb ft)
015RS018
3. Install transmission.
See Transmission section in this manual.
CAUTION: When assembling the engine and
transmission, confirm that dowels have been
mounted in the specified positions at the engine
side. Take care that dowel positions are different
between the manual transmission and the
automatic transmission. Otherwise, the
transmission may be damaged.
012RS009
ENGINE MECHANICAL (6VE1 3.5L) 6A-49
Engine Assembly
Removal
P1010068
1. Disconnect battery ground and positive cable.
2. Remove battery.
3. Make alignment mark on the engine hood and
hinges before removal in order to return the hood
to original position exactly.
4. Remove engine hood.
5. Drain radiator coolant.
6. Disconnect accelerator cable and automatic cruise
control cable from throttle valve on common
chamber.
7. Remove the ECM.
Disconnect the two connectors from the ECM.
. Remove fixing bolts on the common chamber.
Remove fixing bolts for ground cable.
8. Disconnect air duct with air cleaner cover.
9. Remove air cleaner assembly.
10. Disconnect canister vacuum hose.
11. Disconnect vacuum booster hose.
12. Disconnect three engine harness connectors.
13. Disconnect harness connector to transmission (lef
t
front side of engine compartment), disconnect shift
on the fly harness connector from front side o
f
front axle and remove transmission harness
bracket from engine left side.
14. Disconnect ground cable between engine and
frame.
15. Disconnect bonding cable connector on the back
of right dash panel.
16. Disconnect bonding cable terminal on the lef
t
bank.
17. Disconnect starter harness connector from starter.
18. Disconnect generator harness connector from
generator.
19. Disconnect coolant reserve tank hose from
radiator.
20. Remove radiator upper and lower hoses.
21. Remove upper fan shroud.
22. Remove cooling fan assembly four fixing nuts,
then the cooling fan assembly.
23. Move drive belt tensioner to loose side using
wrench then remove drive belt.
24. Remove power steering pump fixing bolts, then
power steering pump. Place the power steering
pump along with piping on the body side.
25. Remove air conditioning compressor fixing bolts
from bracket and place the compressor along with
piping on the body side.
26. Remove four O2 sensor harness connectors (two
each bank) from exhaust front pipe.
27. Remove three exhaust pipe fixing nuts from each
bank.
28. Remove two exhaust pipe fixing nuts from each
exhaust pipe, then move exhaust pipe to rear side
of vehicle.
29. Remove flywheel dust covers.
30. Disconnect two heater hoses from engine.
31. Disconnect fuel hose from right side o
f
transmission.
CAUTION: Plug fuel pipe on engine side and fuel
hose from fuel tank.
32. Remove transmission assembly. Refer to
Transmission section in this manual.
33. Support the engine by engine hoist.
34. Remove two left side engine mount fixing bolts
from engine mount on chassis side.
35. Remove two right side engine mount fixing bolts
from engine mount on chassis side.
36. Remove engine assembly.
Installation
CAUTION: When assembling the engine and
transmission, confirm that dowels have been
mounted in the specified positions at the engine
side. Also take care that dowel positions are
different between the manual transmission and the
automatic transmission. Otherweise, the
transmission may be damaged.
6A-50 ENGINE MECHANICAL (6VE1 3.5L)
012RS009
1. Install engine assembly. Tighten engine mount
fixing bolts to frame to the specified torque.
Torque: 41 N
m (4.2 kg
m/30 lb ft)
2. Reconnect fuel hose to fuel pipe on engine.
3. Install transmission assembly. Refer to
Transmission section in this manual.
4. Reconnect two heater hoses to engine.
5. Install flywheel dust covers.
6. Install exhaust pipe and temporally tighten two
(each bank) rear exhaust flange nuts then tighten
three stud nuts (each bank) between exhaus
t
manifold and exhaust pipe, finally tighten rear side
stud nuts to the specified torque.
Torque: 67 N
m (6.8 kg
m/49 lb ft)
LTW36FSH000101
7. Reconnect O2 sensor connector.
8. Install cooling fan assembly and tighten bolts/nuts
to the specified torque.
Torque: 25 N
m (2.5 kg
m/18 lb ft) for fan pulley
and fan bracket.
Torque : 10 N
m (1.0 kg
m/7 lb ft) for fan and
clutch assembly.
9. Install air conditioner compressor to engine and
tighten to the specified torque.
Torque : 43 N
m (4.4 kg
m/32 lb ft)
10. Install power steering pump, tighten fixing bolt to
the specified torque.
Torque :
M8 bolts : 25 N
m (2.5 kg
m/18 lb ft)
M10 bolts : 43 N
m (4.4 kg
m/32 lb ft)
11. Move drive belt tensioner to loose side using
wrench, then install drive belt to normal position.
850RW001
Legend
(1) Crankshaft Pulley
(2) Cooling Fan Pulley
(3) Tensioner
(4) Generator
(5) Air Conditioner Compressor
(6) Power Steering Oil Pump
(7) Drive Belt
12. Install upper fan shroud.
13. Reconnect radiator upper and lower hoses.
14. Reconnect coolant reserve tank hose to radiator.
15. Reconnect generator harness connector.
16. Reconnect starter harness connector.
17. Reconnect bonding cable terminal on left bank
18. Reconnect bonding cable terminal on the back o
f
right dash panel.
ENGINE MECHANICAL (6VE1 3.5L) 6A-51
19. Reconnect ground cable between engine and
chassis.
20. Reconnect harness connector to transmission and
install transmission harness bracket on engine lef
t
side.
21. Reconnect three engine harness connectors.
22. Reconnect vacuum booster hose.
23. Reconnect canister vacuum hose.
24. Install air cleaner assembly.
25. Reconnect air duct.
26. Reconnect accelerator cable to throttle valve on
common chamber.
27. Install the ECM.
Tighten the four bolts.
Torque : 10 N
m (1.0 kg
m/7 lb ft)
Connect the two connectors.
Tighten the two ground cable bolts.
28. Install engine hood to the origine position.
Refer to installation procedure for Body section
in this manual.
Install accelerator control cable to accelerato
r
cable bracket.
Rotate the ratchet ring in direction an arrow 90
Confirm marking of outer cap must be uppe
r
side.
Slider the lock in direction B.
Confirm ratchet ring is locked.
RTW46ASH000201
Legend
(1) Cable Bracket
(2) Ratchet ring
(3) Outer Cap
(4) Lock
(5) Paint Mark
(6) Arrow Mark
29. Install the cable clips to accelerator control cable.
ENGINE COOLING (6VE1 3.5L) 6B-11
Removal
1. Disconnect battery ground cable.
2. Loosen a drain plug to drain EC.
3. Disconnect oil cooler hose on automatic transmission (A/T).
4. Disconnect radiator inlet hose and outlet hose from the engine.
P1010064
5. Remove fan guide(1), clips(2) on both sides and
the bottom lock, then remove lower fan guide(3)
with fan shroud(4).
RTW46BSH000101
6. Disconnect the reserve tank hose(6) from radiator.
7. Remove bracket(5).
110RW004
8. Lift up and remove the radiator assembly with
hose, taking care not to damage the radiator core
with a fan blade.
Inspection
Radiator Cap
Measure the valve opening pressure of the pressurizing
valve with a radiator filler cap tester.
Replace the cap if the valve opening pressure is outside
the standard range.
Valve opening pressure kPa (psi) 93.3
122.7
(13.5
17.8)
Cap tester: 5 –8840 –0277 –0
Adapter: 5 –8840 –2603 –0
Check the condition of the vacuum valve in the cente
r
of the valve seat side of the cap. If considerable rust or
dirt is found, or if the valve seat cannot be moved by
hand, clean or replace the cap.
ENGINE COOLING (6VE1 3.5L) 6B-13
6. Connect oil cooler hose to automatic transmission.
RTW36BSH000101
7. Connect battery ground cable.
8. Pour engine coolant up to filler neck of radiator, and
up to MAX mark of reserve tank.
RTW36BSH000101
Important operation (in case of 100% engine
coolant change) procedure for filling with engine
coolant.
Engine coolant change
1. To change engine coolant, make sure that the
engine is cool.
WARNING: When the coolant is heated to a high
temperature, be sure not to loosen or remove the
radiator cap. Otherwise you might get scalded by
hot vapor or boiling water. To open the radiato
r
cap, put a piece of thick cloth on the cap and
loosen the cap slowly to reduce the pressure when
the coolant has become cooler.
2. Open radiator cap and drain the cooling system by
loosening the drain valve on the radiator and on the
cylinder body.
NOTE: For best result it is suggested that the engine
cooling system be flushed at least once a year. It is
advisable to flash the interior of the cooling system
including the radiator before using anti-freeze
(ethylene-glycol based).
Replace damaged rubber hoses as the engine
anti-freeze coolant is liable to leak out even mino
r
cracks.
Isuzu recommends to use Isuzu genuine anti-freeze
(ethylen-glycol based) or equivalent, for the cooling
system and not add any inhibitors or additives.
CAUTION: A failure to correctly fill the engine
cooling system in changing or topping up coolant
may sometimes cause the coolant to overflow from
the filler neck even before the engine and radiato
r
are completely full.
If the engine runs under this condition, shortage o
f
coolant may possibly result in engine overheating.
To avoid such trouble, the following precautions
should be taken in filling the system.
3. To refill engine coolant, pour coolant up to filler neck
using a filling hose which is smaller in outside
diameter of the filler neck. Otherwise air between
the filler neck and the filling hose will block entry,
preventing the system from completely filling up.
4. Keep a filling rate of 9 liter/min. or less. Filling ove
r
this maximum rate may force air inside the engine
and radiator.
And also, the coolant overflow will increase, making
it difficult to determine whether or not the system is
completely full.
5.
After filling the system to the full, pull out the filling
hose and check to see if air trapped in the system is
disclodged and the coolant level goes down. Should
the coolant level go down, repeat topping-up until
there is no more drop in the coolant level.