Suzuki 2000 Grand Vitara SQ625 Service Manual page 36

6-32 ENGINE DIAGNOSIS (G16 / J20 ENGINES)
Condition
Overheating
Poor gasoline
mileage
Excessive engine oil
consumption
Possible Cause
D Inoperative thermostat
D Poor water pump performance
D Clogged or leaky radiator
D Improper engine oil grade
D Clogged oil filter or oil strainer
D Poor oil pump performance
D Dragging brakes
D Slipping clutch
D Blown cylinder head gasket
Ignition system out of order.
D Faulty spark plug (improper gap, heavy
deposits, and burned electrodes, etc.)
Engine and emission control system out
of order.
D Fuel pressure out of specification
D Faulty TP sensor, ECT sensor or MAF
sensor
D Faulty EGR system
D Faulty injector
D Faulty ECM (PCM)
Low compression
Others
D Poor valve seating
D Dragging brakes
D Slipping clutch
D Thermostat out of order
D Improper tire pressure
Oil entering combustion chamber
D Sticky piston ring
D Worn piston and cylinder
D Worn piston ring groove and ring
D Improper location of piston ring gap
D Worn or damaged valve stem seal
D Worn valve stem
Reference Item
Thermostat in Engine Cooling
Section.
Water pump in Engine Cooling
Section.
Radiator in Engine Cooling Section.
Engine oil and oil filter change in
Maintenance and Lubrication
Section.
Oil pressure check in Engine
Mechanical Section.
Oil pressure check in Engine
Mechanical Section.
Diagnosis in BRAKES Section.
Diagnosis in Clutch Section.
Cylinder head inspection in Engine
Mechanical Section.
Spark plugs in Ignition System
Section.
Diag. Flow Table B-3 in this Section.
TP sensor, ECT sensor or MAF
sensor in Engine and Emission
Control System Section.
DTC P0400 Diag. Flow Table in this
Section.
Fuel injector in Engine and Emission
Control System Section.
Inspection of ECM (PCM) and its
circuit in this Section.
Previously outlined.
Valves inspection in Engine
Mechanical Section.
Diagnosis in BRAKES Section.
Diagnosis in Clutch Section.
Thermostat in Engine Cooling
Section.
Piston cleaning in Engine
Mechanical Section.
Cylinders, pistons and piston rings
inspection in Engine Mechanical
Section.
Pistons and piston rings inspection in
Engine Mechanical Section.
Pistons installation in Engine
Mechanical Section.
Valves and cylinder head in Engine
Mechanical Section.
Valves inspection in Engine
Mechanical Section.