Power Steering Column Knock Noise; Power Steering Toc-Toc Noise - Ford 2007 WQ Fiesta Repair Manual

100-04-14 Noise, Vibration and Harshness 100-04-14
DIAGNOSIS AND TESTING
Power Steering Column Knock Noise
I. Drive over cobbled stones at low speed 16-40
kmlh (1 0-25 mph) with and without steering
Test Condition
input carefully listening for knock sounds.
Symptom
Power steering system knock1
clonk noise
-
sounds almost
identical to column knock that
occurs when driving and cornering
over cobbled stones or rough
roads. Noise may appear to
emanate from a location closer to
the floor than that for column
knock (Sounds like metallic noise
but is created by pressure impulse
in gear and return line
-
similar to
a sound like quickly turning off a
water tap).
Listen for steering knock noise in the following test
2. Drive over straight tar strips, road rails or 25 mm
conditions with windows closed.
tall harshness strips at low speed 16-40 kmlh
(10-25 mph) both driving straight and with
moderate cornering.
Possible Sources
Power steering return lines.
High power assist gain of power
steering gear valve (steering gear
design
-
no quality issue).
High power steering pump flow
rate (by design).
Power Steering Toc-Toc Noise
1. Turn the steering wheel from left to right abruptly
changing direction.
Test Condition
2. Drive the vehicle for low speed parking
Listen for steering toc-toc noise with the engine
manoeuvres constantly changing steering
speed at idle and the vehicle parked, automatic
direction.
transmission in "P" (PARK) or manual transmission
in neutral and the windows closed.
Action
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
Power steering system column
knock noise
-
a loose sounding
rattle or vibration coming from the
column. Noticeable by hearing
and touch.
2006.0 Fiesta
1212006 G37349en
Possible Sources
Steering column or steering
column
Action
CHECK the steering column
retaining bolts and attachments
to the steering column and secure
if necessary.
REFER to: Specifications (21 1
-
04, Specifications).
Check steering column and inter-
mediate shaft for free play or
loose components.
REFER to: Steering System (2 11
-
00, Diagnosis and Testing).