Subaru 2004 IMPREZA Service Manual page 45

Trouble
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.
Vibration
While engine is running with/
without steering turned.
General Diagnostic Table
Possible cause
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.
Too low engine speed
Vane pump aeration
Damaged valve in oil pump, gearbox
Looseness of play of steering, suspension parts
PS-89
POWER ASSISTED SYSTEM (POWER STEERING)
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.
Adjust and instruct customers.
Fix the wrong part.
Vent air.
Replace the oil pump, faulty parts
of gearbox.
Retighten.
Corrective action