Subaru 2009 IMPREZA Service Manual page 2676

Trouble
Sizzling noise (continuous)
While engine is running.
Whistle (continuous)
While engine is running.
Whine or growl (intermittent or
continuous)
While engine is running with/
without steering turned.
Grinding noise (continuous)
While engine is running with the
steering turned.
Vibration
While engine is running with/
without steering turned.
General Diagnostic Table
Possible cause
Fluid aeration
Damaged pipe of gearbox
Faulty inside of hose or pipe
Flattened hose or pipe
Abnormal inside of oil tank
Removed oil tank cap
Faulty pipe of gearbox or faulty hose
Looseness of oil pump, oil pump bracket attachment
Fault inside of oil pump or hose
Torque converter growl, air conditioner compression growl
Fault inside of gearbox
Faulty steering shaft bearing
Occurs when turning the steering wheel with brakes (ser-
vice or parking) applied.
Engine speed is too low.
Air in vane pump
Damaged valve in oil pump or gearbox
Excessive play in steering, looseness of suspension parts
PS-53
POWER ASSISTED SYSTEM (POWER STEERING)
Fix the faulty part causing aera-
tion.
Replace the fluid and vent air.
Replace the pipe.
Correct or replace.
Replace.
Install cap.
Replace the faulty parts of the
gearbox or the hose.
Retighten.
Replace the oil pump or hose, if
the noise can be heard when
vehicle is running as well as
being stopped.
Remove the power steering pul-
ley belt and check.
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 notify customer.
Repair faulty part
Vent air.
Replace the faulty parts in gear-
box and oil pump.
Retighten.
Corrective action