Jaguar XJ (X350). Manual — part 276

Description of General Steering System Noises

Boom

Rhythmic sound like a drum roll or distant thunder. May cause pressure on the ear drum.

Buzz

Low-pitched sound, like a bee. Usually associated with vibrations.

Chatter

Rapidly repeating metallic sound.

Chuckle

Rapid noise that sounds like a stick against the spokes of a spinning bicycle wheel.

Chirp

High pitched rapidly repeating sound, like chirping birds.

Click

Light sound, like a ball point pen being clicked.

Click/Thump

Heavy metal-to-metal sound, like a hammer striking steel.

Grind

Abrasive sound, like a grinding wheel or sandpaper rubbing against wood.

Groan/Moan

Continuous, low-pitched humming sound.

Groan/Howl

Low, guttural sound, like an angry dog.

Hiss

Continuous sound like air escaping from a tire valve.

Hum

Continuous sound of varying frequencies, like a wire humming in the wind.

Knock

Heavy, loud repeating sound like a knock on a door.

Ping

Similar to knock, except at higher frequency.

Rattle

A sound suggesting looseness, such as marbles rolling around in a can.

Roar

Deep, long, prolonged sound like an animal, or winds and ocean waves.

Rumble

Low, heavy continuous sound like that made by wagons or thunder.

Scrape

Grating noise like one hard plastic rubbing part rubbing against another.

Squeak

High-pitched sound like rubbing a clean window.

Squeal

Continuous, high-pitched sound like running finger nails across a chalkboard.

Tap

Light, hammering sound like tapping pencil on edge of table. May be rhythmic or intermittent.

Weep

Continuous mid-range sound (lower frequency than squeal, higher frequency than groan).

Whir/Whine

High-pitched buzzing sound, like an electric motor or drill.

Whistle

Sharp, shrill sound, like wind passing a small opening.

Description of Specific Steering System Noise Types

Belt Squeal

Belt squeal is a high frequency air-borne noise generated by slippage of the ribbed Vee belt on the

power steering pump pulley. Squeal increases with system loading and at the end of lock.

Clonk

Clonk is a structure-borne noise heard as a loose-sounding rattle or vibration coming from the

steering column. Clonk can be identified by driving and turning over cobblestones, rough roads, or

high frequency bumps such as 25-50 mm tall tar strips. Clonk requires a tie-rod load impact.

Column Knock

Column knock is a loose-sounding rattle or vibration generated by the steering column shaft

contacting other portions of the column assembly. The noise is both audible and tactile. Column

knock is generated by driving over cobblestones or rough pavement. It is not necessary to turn the

steering wheel to create this noise.

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Column Rattle

Column rattle is a metallic sounding noise created when applying a highly impulsive force to the

steering wheel. Column rattle is often used to combine the more general group of column noises

including clonk and column knock. Column rattle noises can be caused by clonk, knock, loose column

components, bonus parts etc. A series of parked, straight-line driving, and cornering test should be

carried out to isolate the source/sources.

Grinding/Scrape

Grinding is a low frequency noise in the column when the steering wheel is turned. Is generally

caused by interference between moving components such as the steering wheel to steering column

shroud.

Grunt (Squawk)

Grunt is a "honking" sound elicited when coming off one of the steering stops. Grunt is generally

excited during parking manoeuvres with a low to medium speed steering input.

Hiss (Swish)

Hiss or Valve Hiss is a high-frequency sound coming from the steering gear when the system is

loaded. It is a rushing or "swish" noise that doesn't change frequency with RPM. Hiss is the general

noise generated by the flow of hydraulic fluid through restrictions in the steering system. Restrictions

include the rotary steering valve, power steering tubes, connectors, tuning orifices, etc. Hiss can be

air-borne and structure-borne, but the structure-borne path through the steering intermediate shaft

is usually dominant.

Moan (Groan)

Moan is the general structure-borne noise of the steering system. Moan is primarily transmitted to

the driver via the body structure through the pump mount, engine mounts, power steering lines and

power steering brackets. On some vehicles, moan is a load humming noise, often present when the

wheel is turned and the system is loaded. It may change frequency with engine RPM and if the

system is loaded or unloaded.

Rack Knock (Rack Slap)

CAUTION: DO NOT attempt to adjust the steering gear yoke. Failure to follow this

instruction will result in the steering gear warranty to become invalid.

Rack Knock is a rattle sound and steering wheel vibration caused by separation of the steering gear

and pinion while driving over bumps. It is a structure-borne noise transmitted through the

intermediate shaft and column. Rack knock can also be heard as a "thump" or impact noise that

occurs with the vehicle stationary when the steering wheel is released from a loaded position and

allowed to return to rest. Noise occurs with the engine on or off.

Rattles

Rattles are noises caused by knocking or hitting with components in the steering system. Steering

rattles can occur in the engine compartment, the suspension, or the passenger compartment .

Rattles can be caused by loose parts, movable and flexible parts, and improper clearances.

Squeaks/Scrapes

Squeaks/Scrapes are noises due to friction or component rubbing anywhere in the steering system.

Squeaks/Scrapes have appeared in steering linkages and joints, in column components and in column

and steering wheel trim parts.

Weep

Weep is an air-borne noise, occasionally generated when turning the steering across lock at a

constant rate. When present on a vehicle the noise, once initiated can often be maintained across a

large proportion of the available steering movement.

Whistle

Whistle is similar to hiss but is louder and of a higher frequency. It is also more of a pure tone noise

than hiss. Whistle is air-borne and is generated by a high flow rate of hydraulic fluid through a small

restriction.

Zip

Zip noise is the air-borne noise generated by power steering pump cavitation when power steering

fluid does not flow freely through the suction hose from the reservoir to the pump. Zip primarily

occurs during cold weather at start-up.

Steering System Vibrations and Harshness

Buzz

Buzz is a tactile rotary vibration felt in the steering wheel for slow steering inputs. Buzz can also be

called a grinding feel and it is closely related to grunt and is caused by high system gain with low

damping. Buzz is generally excited during parking manoeuvres with low to medium speed steering

input.

Buzz (Electrical)

A different steering buzz can be caused by pulse width modulated (PWM) electric actuators used in

variable assist steering systems. This buzz is felt by turning the ignition key to run without starting

the engine and holding onto the steering wheel. In extreme cases, the buzz can be felt with the

engine running also.

Column/Steering Wheel Shake

Column shake is a low frequency vertical vibration excited by primary engine vibrations.

Nibble (Shimmy)

Steering nibble is a rotary oscillation or vibration of the steering wheel, which can be excited at a

specific vehicle speed. Nibble is driven by wheel and tire imbalance exciting a suspension recession

mode, which then translates into steering gear travel and finally steering wheel nibble.

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