Oil Pressure Does Not Rise - Isuzu A-4JA1 Workshop Manual

Checkpoint
Engine oil
OK
Oil pressure gauge or unit
Oil pressure indicator light
OK
Oil filter
OK
Relief valve and by-pass valve
OK
Oil pump
OK
Rocker arm shaft
Continued on the next page
9.

OIL PRESSURE DOES NOT RISE

Trouble Cause
NG Improper viscosity engine oil
Too much engine oil
Defective oil pressure gauge or
NG
unit
Defective indicator light
NG
Clogged oil filter element
Relief valve sticking and/or weak
NG
by-pass valve spring
NG
Clogged oil pump strainer
NG
Worn oil pump related parts
NG
Worn rocker arm bushing
TROUBLESHOOTING
Countermeasure
NG Replace the engine oil
Correct the engine oil volume
Repair or replace the oil pres-
NG
sure gauge or unit
Replace the indicator light
NG Replace the oil filter element or
the oil filter cartridge
Replace the relief valve and/or
NG
the by-pass valve spring
NG
Clean the oil pump strainer
NG Replace the oil pump related
parts
NG
Replace the rocker arm bushing
195