Isuzu 4JB1, Service Information

Page: 8 / 60

00 – 10 SERVICE INFORMATION
6. OVERHEATING
Checkpoint Possible cause Correction
Cooling water Insufficient cooling water Replenish the cooling water
Fan clutch Oil leakage from the fan clutch Replace the fan clutch
Fan belt Fan belt loose or cracked causing slippage Replace the fan belt
Radiator Defective radiator cap or clogged radiator
core Replace the radiator cap or clean the
radiator core
Water pump Defective water pump Repair or replace the water pump
Cylinder head and
cylinder body sealing
cap Defective sealing cap resulting in water
leakage Replace the sealing cap
Thermostat Defective thermostat Replace the thermostat
Cooling system Cooling system clogged by foreign material Clean the foreign material from the
cooling system
Fuel injection timing Fuel injection timing improperly adjusted Adjust the fuel injection timing
7. WHITE EXHAUST SMOKE
Checkpoint Possible cause Correction
Cooling water Insufficient cooling water Replace the cooling water
Fuel Water particles in the fuel Replace the fuel
Fuel injection timing Delayed fuel injection timing Adjust the fuel injection timing
Compression pressure Blown out cylinder head gasket. Worn
cylinder liner.
Piston ring sticking Replace the related parts
Inlet and exhaust valve
Valves seals Defective valve seals.
Worn valves stems and valve guides Replace the valve seals, the valves,
and the valve guides