Suzuki Jimny Service Manual page 382

Condition
Excessive detonation
(The engine makes
sharp metallic knocks
that change with throt-
tle opening.
Sounds like pop corn
popping.)
Overheating
Poor gasoline mileage
Possible Cause
Engine overheating
• Faulty spark plug
• Clogged fuel filter and fuel lines
• Malfunctioning EGR valve (if equipped)
• Poor performance of knock sensor, ECT
sensor or MAP sensor
• Faulty injector
• Faulty ECM
• Excessive combustion chamber deposits
• Inoperative thermostat
• Faulty A/C condenser fan motor or its cir-
cuit
• Loose or slip water pump belt
• Poor water pump performance
• Clogged or leaky radiator
• Improper engine oil grade
• Clogged oil filter or oil strainer
• Poor oil pump performance
• Dragging brakes
• Slipping clutch
• Blown cylinder head gasket
• Faulty ignition coil
• Fuel pressure out of specification
• Faulty TP sensor, ECT sensor or MAP
sensor
• Faulty injector
• Faulty ECM
• Malfunctioning EGR valve (if equipped)
• High idle speed
Low compression
• Poor valve seating
• Dragging brakes
• Slipping clutch
• Thermostat out of order
• Improper tire pressure
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-25
Reference Item
Refer to "Overheating" of this table.
Spark plugs in Section 6F.
Diagnostic Flow Table B-3
EGR system in Section 6E.
Knock sensor in this section, ECT
sensor or MAP sensor in Section 6E.
Diagnostic Flow Table B-1
Inspection of ECM and its circuit in
this section.
Piston and cylinder head in Section
6A1.
Thermostat in Section 6B.
A/C condenser fan control system
check in Section 6E.
ITEM1-1 Drive belt inspection and
change in Section 0B.
Water pump in Section 6B.
Radiator in Section 6B.
ITEM1-3 Engine oil and oil filter
change in Section 0B.
Oil pressure check in Section 6A1.
Oil pressure check in Section 6A1.
Diagnosis Table in Section 5.
Diagnosis Table in Section 7C.
Valves and cylinder head in Section
6A1.
Ignition coil assembly in Section 6F.
Diagnostic Flow Table B-3
TP sensor, ECT sensor or MAP sen-
sor in Section 6E.
Diagnostic Flow Table B-1
Inspection of ECM and its circuit in
this section.
EGR system in Section 6E.
Refer to item "Improper Engine Idle
Speed" previously outlined.
Previously outlined.
Valves and cylinder head in Section
6A1.
Diagnosis Table in Section 5.
Diagnosis Table in Section 7C.
Thermostat in Section 6B.
Refer to Section 3F.