Suzuki Engine 2002 GRAND VITARA SQ420 Service Manual page 181

6-1-40 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H25 ENGINE)
Condition
Engine noise
See NOTE below.
NOTE:
Before checking the mechanical noise, make sure that :
• Ignition timing is properly adjusted.
• Specified spark plug is used.
• Specified fuel is used.
Possible Cause
Valve noise
• Faulty hydraulic valve lash adjuster
• Worn valve stem and guide
• Weak or broken valve spring
• Warped or bent valve
• Loose camshaft housing bolts
Piston, ring and cylinder noise
• Worn piston, ring and cylinder bore
Connecting rod noise
• Worn crankpin bearing
• Worn crankpin
• Loose connecting rod nuts
• Low oil pressure
Crankshaft noise
• Low oil pressure
• Worn crankshaft journal bearing
• Worn crankshaft journal
• Loose lower crankcase (bearing cap)
bolts
• Excessive crankshaft thrust play
Correction
"Camshaft and Valve Lash Adjuster" in Sec-
tion 6A2.
"Valves and Cylinder Heads" in Section
6A2.
"Valves and Cylinder Heads" in Section
6A2.
"Valves and Cylinder Heads" in Section
6A2.
"Camshaft and Valve Lash Adjuster" in Sec-
tion 6A2.
"Piston, Piston Rings, Connecting Rods and
Cylinders" in Section 6A2.
"Piston, Piston Rings, Connecting Rods and
Cylinders" in Section 6A2.
"Piston, Piston Rings, Connecting Rods and
Cylinders" in Section 6A2.
"Piston, Piston Rings, Connecting Rods and
Cylinders" in Section 6A2.
Previously outlined.
Previously outlined.
"Main Bearings, Crankshaft and Cylinder
Block" in Section 6A2.
"Main Bearings, Crankshaft and Cylinder
Block" in Section 6A2.
"Main Bearings, Crankshaft and Cylinder
Block" in Section 6A2.
"Main Bearings, Crankshaft and Cylinder
Block" in Section 6A2.