4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–419
CRANKSHAFT POSITION (CKP)
SENSOR
Location
Installed to the clutch housing.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect connector from the CKP sensor.
3. Loosen a bolt and remove the CKP sensor from the
clutch housing.
Installation Procedure
1. Install the CKP sensor to the clutch housing.
2. Tighten CKP sensor by a bolt with specified
tightening torque.
Tightening Torque
Bolts: 8.0 - 12.0 N·m (0.8 - 1.2 kgf·m)
3. Connect a CKP sensor connector to the CKP
sensor.
4. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
ENGINE COOLANT TEMPERATURE
(ECT) SENSOR
Location
Installed to the thermostat housing.
Removal Procedure
1. Disconnect the negative battery cable.
2. Drain enough engine coolant so that the coolant
level will be below the ECT sensor.
3. Disconnect connector from the ECT sensor.
4. Loosen and remove the ECT sensor from the
thermostat housing.
NOTE: Cool down the engine before above procedures
are carried out.
Installation Procedure
1. Apply sealer to threads of screw at the ECT sensor.
2. Tighten the ECT sensor with specified tightening
torque.
Tightening Torque
Bolt: 13N·m (1.3kgf·m)
3. Connect a ECT sensor connector to the ECT
sensor.
4. Fill the engine coolant.
5. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
Verify no engine coolant leaking from the sensor
threads after replacement.
ENGINE MECHANICAL (6VE1 3.5L) 6A-11
Symptom Possible Cause Action
Engine overheating Level of Engine Coolant too low Replenish
Fan clutch defective Replace
Thermostat defective Replace
Engine Coolant pump defective Correct or replace
Radiator clogged Clean or replace
Radiator filler cap defective Replace
Level of oil in engine crankcase too
low or wrong engine oil Change or replenish
Resistance in exhaust system
increased Clean exhaust system or replace
defective parts
Throttle Position Sensor adjustment
incorrect Replace with Throttle Valve ASM
Throttle Position Sensor circuit open
or shorted Correct or replace
Cylinder head gasket damaged Replace
Engine overcooling Thermostat defective Replace (Use a thermostat set to
open at 82C (180F))
Engine lacks compression ———— Refer to Hard Start
Others Tire inflation pressure abnormal Adjust to recommended pressures
Brake drag Adjust
Clutch slipping Adjust or replace
Level of oil in engine crankcase too
high Correct level of engine oil
EGR valve defective Replace
ENGINE MECHANICAL (6VE1 3.5L) 6A-39
Valve Stem Oil Controller, Valve Spring and Valve Guide
Removal
1. Disconnect battery ground cable.
Drain engine oil.
2. Drain engine coolant.
3. Remove cylinder head assembly.
Refer to removal procedure for Cylinder Head
in this manual.
4. Remove camshaft.
Refer to removal procedure for Camshaft in this
manual.
5. Remove tappets with shim.
NOTE: Do not damage shim surface.
6. Remove valve springs using 5884024460
valve spring compressor and 5884025470
valve spring compressor adapter then remove
upper valve spring seat and lower seat.
014RW042
7. Remove oil controller using 5884006230 oil
controller remover, remove each valve stem oil
controller.
8. Remove valve guide using 5884025490 valve
guide replacer.
Installation
1. Install valve guide using 5884024420 valve
guide installer.
2. Install oil controller using 5884006240 oil
controller installer.
3. Install lower valve spring seat, valve spring and
upper valve spring seat then put split collars on the
upper spring seat, using 5884024420 valve
spring compressor and 5884006240 valve
spring compressor adapter to install the spli
t
collars.
014RW042
4. Install tappet with shim.
5. Install camshaft assembly.
Refer to installation procedure for Camshaft in
this manual.
6. Install cylinder head assembly.
Refer to installation procedure for Cylinde
r
Head in this manual.
7. Fill engine oil until full level.
8. Fill engine coolant.
ENGINE COOLING (6VE1 3.5L) 6B-5
Diagnosis
Engine Cooling Trouble
Symptom Possible Cause Action
Engine overheating Low Engine Coolant level Replenish
Thermo meter unit faulty Replace
Faulty thermostat Replace
Faulty Engine Coolant temperature
sensor Repair or replace
Clogged radiator Clean or replace
Faulty radiator cap Replace
Low engine oil level or use of
improper engine oil Replenish or change oil
Clogged exhaust system Clean exhaust system or replace
faulty parts
Faulty Throttle Position sensor Replace throttle valve assembly
Open or shorted Throttle Position
sensor circuit Repair or replace
Damaged cylinder head gasket Replace
Engine overcooling Faulty thermostat Replace
Engine slow to warm–up Faulty thermostat Replace
Thermo unit faulty Replace
6B-6 ENGINE COOLING (6VE1 3.5L)
Draining and Refilling Cooling
System
Before draining the cooling system, inspect the system
and perform any necessary service to ensure that it is
clean, does not leak and is in proper working order.
The engine coolant (EC) level should be between the
“ MIN" and “MAX" lines of reserve tank when the engine
is cold. If low, check for leakage and add EC up to the
“ MAX" line.
There should not be any excessive deposit of rust o
r
scales around the radiator cap or radiator filler hole, and
the EC should also be free from oil.
Replace the EC if excessively dirty.
1. Completely drain the cooling system by opening the
drain plug at the bottom of the radiator.
P1010064
2. Remove the radiator cap.
WARNING: To avoid the danger of being burned, do
not remove the cap while the engine and radiato
r
are still hot. Scalding fluid and steam can be blown
out under pressure.
3. Disconnect all hoses from the EC reserve tank.
Scrub and clean the inside of the reserve tank with
soap and water. Flush it well with clean water, then
drain it. Install the reserve tank and hoses.
4. Refill the cooling system with the EC using a
solution that is 50 percent antifreeze.
Procedure for filling with coolant (in case of full change)
Make sure that the engine is cool.
Open radiator cap pour coolant up to filler neck.
Pour coolant into reservoir tank up to “MAX" line.
Tighten radiator cap and start the engine. Afte
r
idling for 2 to 3 minutes, stop the engine and reopen
radiator cap. If the water level is lower, replenish.
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
not 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.
After tightening radiator cap, warm up the engine at
about 2000 rpm. Set heater adjustment to the
highest temperature position, and let the coolan
t
circulate also into heater water system.
Check to see the thermostat has opened through
the needle position of water thermometer, conduct a
5 –minute idling again and stop the engine.
When the engine has been cooled, check filler neck
for water level and replenish if required. Should
extreme shortage of coolant is found, check the
cooling system and reservoir tank hose for leakage.
Pour coolant into the reservoir tank up to “MAX"
line.
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.
6B-14 ENGINE COOLING (6VE1 3.5L)
6. After directly filling the radiator, fill the reservoir to
the maximum level.
7. Install and tighten radiator cap and start the engine.
After idling for 2 to 3 minutes, stop the engine and
reopen radiator cap. If the water level is lower,
replenish.
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.
8.
After tightening radiator cap, warm up the engine at
about 2,000 rpm.
Set heater adjustment to the highest temperature
position, and let the coolant circulate also into
heater water system.
9. Check to see the thermostat has opened through
the needle position of water thermometer, conduct a
5-minute idling again and stop the engine.
10. When the engine has been cooled, check filler neck
for water level and replenish if required. Should
extreme shortage of coolant is found, check the
coolant system and reservoir tank hose for leakage.
11. Fill the coolant into the reservoir tank up to “MAX"
line.
6E-62 3.5L ENGINE DRIVEABILITY AND EMISSIONS
GENERAL DESCRIPTION FOR EXHAUST
GAS RECIRCULATION (EGR) SYSTEM
Linear EGR Valve
060R200237
Legend
(1) ECM
(2) Linear EGR Valve
(3) Throttle
(4) Exhaust Manifold
The exhaust gas re-circulation (EGR) system is used to
reduce emission levels of oxides of nitrogen (NOx).
NOx emission levels are caused by a high combustion
levels by decreasing the combustion temperature.
The EGR valve feeds small amount of exhaust gas
back into the combustion chamber. The fuel/air mixture
will be diluted and combustion temperatures reduced.
Linear EGR valve Operation and Results o
f
Incorrect Operation
The linear EGR valve is designed to accurately supply
EGR to the engine independent of intake manifold
vacuum. The valve controls EGR flow from the exhaus
t
to the intake manifold through an orifice with a ECM
controlled pintle. During operation, the ECM controls
pintle position by monitoring the pintle position feedback
signal.
The linear EGR valve is activated under the following
conditions:
No DTC relating to the EGR.
Engine speed is between 1200 and 4375rpm.
Engine coolant temperature is between 20 and
100.
Throttle position sensor output voltage is belo
w
3V.
Too mach EGR flow at idle, cruise or cold operation
may cause any of the following conditions to occur:
Engine stalls after a cold start.
Engine stalls at idle after deceleration.
Vehicle surges during cruise.
Rough idle.
Too little or no EGR flow may allow combustion
temperatures to get too high. This could cause:
Spark knock (detonation).
Emission test failure.
Poor fuel economy.