Engine Symptom Diagnosis - Suzuki 2006 SX4 Service Manual

Engine Symptom Diagnosis

Perform troubleshooting referring to the followings when ECM has detected no DTC and no abnormality has been
found in "Visual Inspection" and "Engine Basic Inspection".
Condition
Hard starting (Engine
cranks OK)
Low oil pressure
Engine noise – Valve
noise
NOTE
Before checking
mechanical noise, make
sure that:
• Specified spark plug is
used.
• Specified fuel is used.
Possible cause
Faulty spark plug
Faulty ignition coil
Dirty or clogged fuel hose or pipe
Malfunctioning fuel pump
Air drawn in through intake manifold
gasket or throttle body gasket
Faulty electric throttle body assembly
Faulty APP sensor assembly
Faulty ECT sensor or MAF sensor
Faulty ECM
Low compression
Poor spark plug tightening or faulty
gasket
Compression leak from valve seat
Sticky valve stem
Weak or damaged valve springs
Compression leak at cylinder head
gasket
Sticking or damaged piston ring
Worn piston, ring or cylinder
Malfunctioning PCV valve
Improper oil viscosity
Malfunctioning oil pressure switch
Clogged oil strainer
Functional deterioration of oil pump
Worn oil pump relief valve
Excessive clearance in various sliding
parts
Improper valve lash
Worn valve stem and guide
Weak or broken valve spring
Warped or bent valve
Engine General Information and Diagnosis:
Correction / Reference Item
"Spark Plug Inspection in Section 1H"
"Ignition Coil Assembly (Including ignitor)
Inspection in Section 1H"
"Fuel Pressure Check"
"Fuel Pressure Check"
Check air intake system.
"Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C"
"Accelerator Pedal Position (APP) Sensor
Assembly Inspection in Section 1C"
"Engine Coolant Temperature (ECT) Sensor
Inspection in Section 1C" or "Mass Air Flow
(MAF) and Intake Air Temperature (IAT)
Sensor Inspection in Section 1C"
"Inspection of ECM and Its Circuits".
"Compression Check in Section 1D"
"Spark Plug Removal and Installation in
Section 1H"
"Valves and Valve Guides Inspection in
Section 1D"
"Valves and Valve Guides Inspection in
Section 1D"
"Valve Spring Inspection in Section 1D"
"Cylinder Head Inspection in Section 1D"
"Pistons, Piston Rings, Connecting Rods and
Cylinders Inspection and Cleaning in Section
1D"
"Pistons, Piston Rings, Connecting Rods and
Cylinders Inspection and Cleaning in Section
1D"
"PCV Valve Inspection in Section 1B"
"Engine Oil and Filter Change in Section 0B"
"Oil Pressure Switch Inspection in Section 9C"
"Oil Pan and Oil Pump Strainer Cleaning in
Section 1E"
"Oil Pump Inspection in Section 1E"
"Oil Pump Inspection in Section 1E"
—
"Camshaft, Tappet and Shim Inspection in
Section 1D"
"Valves and Valve Guides Inspection in
Section 1D"
"Valve Spring Inspection in Section 1D"
"Valves and Valve Guides Inspection in
Section 1D"
1A-49
S6RW0C1104011