1A-49 Engine General Information and Diagnosis:
Low oil pressure Improper oil viscosity “Engine Oil and Filter Change: in Section 0B”
Malfunctioning oil pressure switch “Oil Pressure Switch Inspection: in Section
9C”
Clogged oil strainer “Oil Pan and Oil Pump Strainer Cleaning: For
J20 Engine in Section 1E” or “Oil Pan and Oil
Pump Strainer Cleaning: For M16A Engine
with VVT in Section 1E”
Functional deterioration of oil pump “Oil Pump Inspection: For J20 Engine in
Section 1E” or “Oil Pump Inspection: For M16A
Engine with VVT in Section 1E”
Worn oil pump relief valve “Oil Pump Inspection: For J20 Engine in
Section 1E” or “Oil Pump Inspection: For M16A
Engine with VVT in Section 1E”
Excessive clearance in various sliding
parts
Engine noise – Valve
noise
NOTE
Before checking
mechanical noise, make
sure that:
• Specified spark plug is
used.
• Specified fuel is used.
Improper valve lash “Camshaft, Tappet and Shim Inspection: For
J20 Engine in Section 1D” or “Camshaft,
Tappet and Shim Inspection: For M16A Engine
with VVT in Section 1D”
Worn valve stem and guide “Valves and Valve Guides Inspection: For J20
Engine in Section 1D” or “Valves and Valve
Guides Inspection: For M16A Engine with VVT
in Section 1D”.
Weak or broken valve spring “Valve Spring Inspection: For J20 Engine in
Section 1D” or “Valve Spring Inspection: For
M16A Engine with VVT in Section 1D”
Warped or bent valve “Valves and Valve Guides Inspection: For J20
Engine in Section 1D” or “Valves and Valve
Guides Inspection: For M16A Engine with VVT
in Section 1D”.
Engine noise – Piston,
ring and cylinder noise
NOTE
Before checking
mechanical noise, make
sure that:
• Specified spark plug is
used.
• Specified fuel is used.
Worn piston, ring and cylinder bore “Pistons, Piston Rings, Connecting Rods and
Cylinders Inspection and Cleaning: For J20
Engine in Section 1D” or “Cylinders, Pistons
and Piston Rings Inspection: For M16A Engine
with VVT in Section 1D”
Condition Possible cause Correction / Reference Item