Engine noise – Valve noise
Perform troubleshooting referring to the followings when ECM has detected no DTC and no abnormality has been found in Visual Inspection:M13A with VVT and Engine Basic Inspection:M13A with VVT .
Condition Possible Cause Action
Engine noise – Valve noise
Before checking mechanical noise, make sure that: 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