Power Steering Hiss Noise; Power Steering Lock Stop Impact Knock Noise; Power Steering Mechanical Knock Noise (Pas Off) - Ford 2007 WQ Fiesta Repair Manual

I 00-04-1 2
Noise, Vibration and Harshness
I 00=04m12
DIAGNOSIS AND TESTING
Power Steering Hiss Noise
Test Condition
Listen for steering hiss noise with the vehicle
parked, transmission in neutral and all windows -
closed in the following test conditions.
Power Steering Lock Stop Impact Knock 1. Turn the steering wheel to the left-hand and
Noise
right-hand steering locks and listen for the
impact noise.
Test Condition
Listen for steering knock noise with the engine
speed at idle in the following test conditions (noise
also apparent with engine off).
Action
CHECK the installation and
potential damage of the floor seal.
Certain amount of noise level
acceptable, not a safety critical
item.
Certain amount of noise level
acceptable, not a safety critical
item.
Certain amount of noise level
acceptable, not a safety critical
item.
Symptom
N0TE:Engine speed at idle
turning the steering wheel slowly
lock to lock.
Power steering system hiss noise
-
a high frequency, continuous
rush or swish noise like escaping
air from a balloon. Hiss occurs
while turning between the steering
lock stops, all steering angles.
Noise does not change with
engine rpm and is worse at high
operating temperatures.
N0TE:Engine speed at idle
holding the steering wheel against
a steering lock for three seconds.
Do not hold for more than five
seconds.
Power steering system hiss noise
-
a continuous noise like escaping
air occurs while holding the
steering against a steering lock
stop.
Possible Sources
Floor seal.
Power steering gear valve design.
Power steering system hydraulic
design.
Power pump pressure
relief valve.
Power Steering Mechanical Knock Noise
1. Turn the steering wheel 90 degrees to the right,
(PAS off) hold and then quickly release.
2. Turn the steering wheel 90 degrees to the left,
Test Condition
hold and then quickly release.
Listen for steering knock noise with the engine off
in the following test conditions (no power assist).
2006.0 Fiesta
1212006
G37349en
Action
Certain amount of noise level
acceptable, not a safety critical
item.
Symptom
Power steering system knock
noise
-
a heavy loud sound like a
knock on a door that occurs in
parking condition when hitting the
lock stop.
Possible Sources
Power steering gear mechanical
noise, metal to metal at end of
steering travel.