1998 ISUZU TROOPER 6b engine cooling

6A2 Ð 2 4JG2-NA/4JG2-TURBO ENGINE
RECARD Comet V Type swirl combustion chamber which
provides superior driving performance, fuel economy and
silent combustion over a wide range of driving
conditions, is applied.
The cylinder head gasket is of laminated steel sheets.
Three grades of the gasket according to the measured
piston head projection from the cylinder block are
provided to give the engine a minimum compression
ration fluctuation.
The cylinder head fixing blots, flywheel bolts and con-
necting rod fixing bolts are tightened by the angular
Tightening Method.
The chrome plated steel dry type (Chromard) cylinder
liners provide the highest durability.
Auto-thermatic pistons having steel struts with 0.7 mm
offset from the piston pin center line, ate applied to
reduce thermal expansion and resulting engine noise
when the engine is cold.
The crankshaft bearings and connecting rod bearings are
of aluminum having a high bearing surface.
These bearing are especially sensitive to foreign material
such as metal scraps. So, it is very important that the oil
ports and other related surfaces are kept clean and free of
foreign material.
Crank shaft bearing selection for optimum bearing and
journal clearance is applied to reduce vibration and noise.
As tufftriding (Nitrizing treatment) is applied to increase
crankshaft strength, crankpins and journals should not be
reground.
An oiling jet device for piston cooling is provided in the
lubricating oil circuit from cylinder block oil gallery via a
check valve.
Take care not to damage any oiling jet when removing
and installing piston and connecting assembly.
The DFI (Double Formation Injection) Pintaux Type
injection nozzle having a sub-injection hole is applied.
This nozzle contributes to substantially minimize the
diesel knocking sound noticeable in the cold engine idling
operation.
Install the injection nozzle, directing the sub-injection hole
to the specified direction.
QOS III preheating system which features a quick-on glow
plug with thermometer control of the glowing time and
the afterglow time function, is applied.

4JG2-NA/4JG2-TURBO ENGINE 6A2 Ð 15
TIMING GEAR
REMOVAL
Preparation:
·Disconnect battery ground cable.
·Drain coolant.
1. P/S Pump Drive Belt
·Loosen P/S pump mounting bolt and adjust bolt,
and remove the drive belt.
2. AC Generator Drive Belt
·Loosen AC Generator mounting bolt (under side)
and adjust plate lock bolt, and remove the drive
belt.
3. Cooling Fan Assembly
·Remove clamp nut, and remove cooling fan asm,
distant pipe, and fan pulley.
4. Crankshaft Damper Pulley
5. Upper Noise Shield Cover
6. Lower Noise Shield Cover
7. Noise Cover Spacer.
8. Timing Gear Case Cover
9. Oil Pipe
10. Idler Gear ÒBÓ and Shaft
1) Measure the camshaft timing gear backlash and the
crenkshaft timing gear backlash before removing the
idler gear.

6A2 Ð 20 4JG2-NA/4JG2-TURBO ENGINE
4. Cranshaft Damper Pulley
Tighten the crankshaft damper pulley bolt to the specified
torque.
NOTE:
Hold the flywheel ring gear stationary to prevent the
crankshaft from turning when tightening the damper
pulley.
3. Cooling Fan Assembly
·Mount fan pulley, distance piece, and cooling fan
asm (in this order) on the water pump, and
tighten to the specified torque.
2. AC Generator Drive Belt
·Install AC Generator drive belt and adjust belt
tension.
·Refer to Drive Belt Adjustment in section 6B.
1. P/S Pump Drive Belt
·Install P.S pump drive belt and adjust belt tension.
·Refer to Drive Belt Adjustment in section 6B.
206(21/152)N·m(Kg·m/lb·ft)
206(21/152)N·m(Kg·m/lb·ft)

4JG2-NA/4JG2-TURBO ENGINE 6A2 Ð 49
3. Cooling Fan Assembly
·Remove cooling fan asm fixing nuts, cooling fan
asm, fan pulley and center.
4. Radiator Assembly
·Remove bracket and radiator asm.
5. Air Cleaner Cover & Air Duct
6. Intercooler Assembly (4JG2 -T only)
·(Refer to Intercooler removal steps in this section)
7. P/S Pump Drive Belts
·Loosen P/S pump fixing bolts and adjusting bolt
and remove two drive belts.
8. P/S Pump Assembly
·Remove two fixing bolts (front side), a fixing nut
(rear side) and support P/S pump asm with oil
hoses by tying to body side.
9. Engine Ground Cable
·Disconnect ground cable from A/C compressor
bracket.
10. AC Generator Harness
·Disconnect B terminal and harness connector
from AC generator.
11. A/C Compressor Assembly
·Remove A/C compressor fixing bolt (rear under
side of compressor) by using a long extension bar
at under side of wheel arch.
·Disconnect magnetic clutch harness connector.
·Remove fixing bolts (upper and front lower side
of compressor) and set A/C compressor asm with
pipe lines on battery carrier.
12. Vacuum Hose: Vacuum Pump
·Disconnect vacuum hose from vacuum pump.
13. Starter Harness
·Disconnect B terminal and put cable harness close
to chassis side.
·Disconnect S terminal connector.
14. Engine Harness.
·Disconnect engine harness close to engine side.
15. Accelerater Cable
·Loosen locking nut at bracket and disconnect
accelerater cable from injection pump control
lever.
16. Fuel Hoses
·Disconnect fuel hoses from injection pump side
and take care not to spill fuel and enter dust.
17. Engine Ground Cable
·Disconnect ground cable from left rear side of
timing gear case.

6A2 Ð 52 4JG2-NA/4JG2-TURBO ENGINE
6. Intercooler Assembly (4JG2-T Only)
·Refer to intercooler installation steps in this
section.
5. Air Cleaner Cover & Duct
4. Radiator Assembly
·Install cushion rubber in under left and right part
of radiator and position radiator.
·Fix radiator by bracket.
3. Cooling Fan Assembly
·Install cooling fan asm and tighten fixing bolts to
the specified torque.
2. Fan Shroud
1. Radiator Hose
·Connect upper and lower hose to engine side.
·Pour coolant in to radiator.
·Install battery.
·Connect window washer hose.
10. A.C. Generator Harness
9. Engine Ground Cable
·Attached ground cable to A/C compressor bracket.
8. P/S Pump Assembly
·Install P/S pump asm in engine and tighten
temporarily fixing nut.
7. P/S Pump Drive Belt
·Install drive belts adjust belt tension by adjusting
bolt and tighten locking bolt to the specified
torque.
·Refer to ÒDrive Belt AdjustmentÓ in section 6B.
8 (0.8/69)N·m(Kg·m/lb·in)
40 (4.1/30)N·m(Kg·m/lb·ft)

ENGINE COOLING 6B Ð 1
SECTION 6B
ENGINE COOLING
CONTENTS
PAGE
General Description ..................................................................................................................... 6B- 1
On-Vehicle Service ....................................................................................................................... 6B- 5
Water Pump ............................................................................................................................. 6B- 5
Thermostat ............................................................................................................................... 6B- 7
Radiator .................................................................................................................................... 6B- 9
Drive Belt Adjustment ............................................................................................................ 6B-15
GENERAL DESCRIPTION

6B Ð 2 ENGINE COOLING

ENGINE COOLING 6B Ð 3
The cooling system is a pressurized coolant forced
circulation type which consists of water pump, thermostat
cooling fan, radiator and other components. The
circulating coolant cools the lubricating oil in the oil filter
and turbocharger.
WATER PUMP
The coolant pump is a centrifugal impeller type and is
driven by V type drive belt.
THERMOSTAT
The thermostat is a wax pellet type with a jiggle valve and
is installed in the thermostat housing.
RADIATOR
The radiator is a tube type with corrugated fins. In order
to raise the boiling point of coolant, the radiator is fitted
with a cap in which the valve is operated under the
pressure.