Isuzu AA-6HK1T, Workshop Manual

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0A–28 GENERAL INFORMATION
Condition Possible Cause Correction
Trouble in the fuel system
Trouble in the air intake system
Improper idle speed
Trouble in the cooling system
Trouble in the lubricating system
Trouble in turbocharger system
Low compression pressure
Trouble in the valve gear train
Fuel leakage
Injection nozzle starting pressure too
low
Improper spray condition
Injection timing improperly adjusted
Clogged air cleaner element
Poorly adjusted idling speed
Defective thermostat
Improper engine oil viscosity
Air leakage from the turbocharger intake
side
Defective turbocharger assembly
Blown out cylinder head gasket
Worn cylinder liner
Piston ring sticking or broken
Improper seating between the valve and
valve seat.
Valve clearance improperly adjusted
Worn camshaft lobe
Valve spring weak or broken
Repair or replace the fuel system
related parts
Adjust or replace the injection nozzle
Adjust or replace the injection nozzle
Adjust the injection timing
Clean or replace air cleaner element
Adjust idling speed
Replace
Replace engine oil
Repair the turbocharger intake side
Replace the turbocharger assembly
Replace the related parts
Adjust the camshaft
Replace the camshaft
Replace the valve spring
4. Excessive Fuel Consumption
Condition Possible Cause Correction
Trouble in the lubricating system
Leakage
Oil leaking into the combustion
chamber due to poor seal in the
valve system
Improper sealing
Low compression pressure
Poor engine ventilation
Engine oil unsuitable
Too much engine oil
Oil leakage from the oil seal and/or
gasket
Worn valve stems and valve guides
Worn valve stem oil seal
Worn or broken seal ring in the
turbocharger
Blown out cylinder head gasket
Worn cylinder liner
Piston ring sticking or broken
Improper seating between the valve and
valve seat.
Clogged air breather
Replace engine oil
Correct engine oil volume
Replace the oil seal and/or gasket
Replace the intake and exhaust valves
and valve guides
Replace the oil seal
Replace the seal ring
Replace the related parts
Clean the air breather
5. Excessive Oil Consumption