Engine Lubrication System — Lubrication Circuit
LC-53flowchartCD17 uses a Valve lifter; CD20 uses a Hydraulic valve lifter. Diagram applies to the CD diesel engine.
Lubrication Circuit
NOTE
— Arrow legend: solid arrow = Oil gallery in cylinder block; hollow arrow = Oil passage; half-shaded arrow = By-pass passage.
Lubrication Circuit Flow
Probable Cause
Corrective Action
Oil pump
Oil filter
Oil pump
Regulator valve
Oil filter
Relief valve
Oil filter
Oil cooler
Oil cooler
Relief valve
Oil cooler
Main bearing
Oil cooler
Cylinder head oil gallery
Oil cooler
Oil feed hose
Main bearing
Crankshaft
Crankshaft
Connecting rod bearing
Connecting rod bearing
Connecting rod
Connecting rod
Piston and cylinder wall
Oil feed hose
Vacuum pump
Vacuum pump
Oil return hose
Cylinder head oil gallery
CD17: Valve lifter / CD20: Hydraulic valve lifter
Cylinder head oil gallery
Camshaft bracket
Camshaft bracket
Camshaft journal
Camshaft journal
Cam lobe
Oil strainer
Oil pump
Piston and cylinder wall
Oil return hose
Cam lobe
Oil pan
Oil pan
Oil strainer
Cause
Oil pump
Fix
Oil filter
Cause
Oil pump
Fix
Regulator valve
Cause
Oil filter
Fix
Relief valve
Cause
Oil filter
Fix
Oil cooler
Cause
Oil cooler
Fix
Relief valve
Cause
Oil cooler
Fix
Main bearing
Cause
Oil cooler
Fix
Cylinder head oil gallery
Cause
Oil cooler
Fix
Oil feed hose
Cause
Main bearing
Fix
Crankshaft
Cause
Crankshaft
Fix
Connecting rod bearing
Cause
Connecting rod bearing
Fix
Connecting rod
Cause
Connecting rod
Fix
Piston and cylinder wall
Cause
Oil feed hose
Fix
Vacuum pump
Cause
Vacuum pump
Fix
Oil return hose
Cause
Cylinder head oil gallery
Fix
CD17: Valve lifter / CD20: Hydraulic valve lifter
Cause
Cylinder head oil gallery
Fix
Camshaft bracket
Cause
Camshaft bracket
Fix
Camshaft journal
Cause
Camshaft journal
Fix
Cam lobe
Cause
Oil strainer
Fix
Oil pump
Cause
Piston and cylinder wall
Cause
Oil return hose
Cause
Cam lobe
Fix
Oil pan
Cause
Oil pan
Fix
Oil strainer