Subaru Impreza 2002 Service Manual page 3154

Trouble
Hiss noise (continuous)
While engine is running.
Rattling noise (intermittent) While
engine is running.
Knocking
When turning steering wheel in
both direction with small angle
repeatedly at engine ON or OFF.
Grinding noise (continuous)
While engine is running.
Squeal, squeak (intermittent or
continuous)
While engine is running.
Sizzling noise (continuous)
While engine is running.
Whistle (continuous)
While engine is running.
Whine or growl (continuous or
intermittent)
While engine is running with/
without steering turned.
Creaking noise (intermittent)
While engine is running with
steering turned.
GENERAL DIAGNOSTIC TABLE
Possible cause
Relief valve emits operating sound when steering wheel is
completely turned in either direction. (Don't keep this con-
dition over 5 seconds.)
Relief valve emits operating sound when steering wheel is
not turned. This means that the relief valve is faulty.
Interference with adjacent parts
Loosened installation of oil pump, oil tank, pump bracket,
gearbox or crossmember
Loosened installation of oil pump pulley or other pulley(s)
Loosened linkage or play of steering or suspension Loos-
ened tightening of joint or steering column
Sound generates from the inside of gearbox or oil pump.
Excessive backlash
Loosened lock nut for adjusting backlash
Loosened tightening or play of tie-rod, tie-rod end
Vane pump aeration
Vane pump seizing
Pulley bearing seizing of oil pump
Folded hose, flat pipe
Maladjustment of pulley belt
Damaged or charged pulley belt
Unequal length of pulley belts
Run out or soilage of V-groove surface of oil pump pulley
Fluid aeration
Damaged pipe of gearbox
Abnormal inside of hose or pipe
Flat hose or pipe
Abnormal inside of oil tank
Removed oil tank cap
Abnormal pipe of gearbox or abnormal inside of hose
Loosened installation of oil pump, oil pump bracket
Abnormal inside of oil pump, hose
Torque converter growl, air conditioner compression growl
Abnormal inside of gearbox
Abnormal bearing for steering shaft
Generates when turning steering wheel with brake (ser-
vice or parking) applied.
PS-111
POWER ASSISTED SYSTEM (POWER STEERING)
Normal
Defective
Replace the oil pump.
Check the clearance.
Correct if necessary.
<Ref. to PS-78, INSPECTION,
Pipe Assembly [LHD
MODEL].><Ref. to PS-86,
INSPECTION, Pipe Assembly
[RHD MODEL].>
Retighten.
Retighten.
Retighten or replace.
Replace the faulty parts of gear-
box or oil pump.
Adjust and retighten.
Retighten or replace.
Inspect and retighten the fluid
line connection.
Refill fluid and vent air.
Replace the oil pump.
Replace the oil pump.
Replace.
Adjust or replace.
(Replace two belts as a set.)
Clean or replace.
Fix the wrong part causing aera-
tion.
Replace the fluid and vent air.
Replace the pipe.
Rectify or replace.
Replace.
Install the cap.
Replace the faulty parts of gear-
box or hose.
Retighten.
Replace the oil pump, hose, if the
noise can be heard when running
as well as stand still.
Remove the power steering pul-
ley belt and confirm.
Replace the faulty parts of gear-
box.
Apply grease or replace.
If the noise goes off when brake
is released, it is normal.
Corrective action