Engine noise
Perform troubleshooting referring to the followings when ECM has detected no DTC and no abnormality has been found in Visual Inspection:M13A without VVT and Engine Basic Inspection:M13A without VVT .
Condition Possible Cause Action
Engine noise
Before checking the mechanical noise, make sure that:
Ignition timing is properly adjusted.
Specified spark plug is used.
Specified fuel is used.
Improper valve lash
Worn valve stem and guide
Weak or broken valve spring
Warped or bent valve
Loose camshaft housing bolts
Worn piston, ring and cylinder bore
Worn crank pin bearing
Worn crank pin
Loose connecting rod nuts
Low oil pressure
Condition “Low Oil Pressure”
Worn crankshaft journal bearing
Worn crankshaft journal
Loose lower crankcase (bearing cap) bolts
Excessive crankshaft thrust play