343                                                                   sound ________________________________________________________________________sound - Vibrations found occurring in air, water, and other mediums  which stimulate a person's auditory nerves causing a person to hear a  specific sound.  Cars emit a variety of sounds that can be normal or  abnormal.  They can be grouped into five categories: intake, exhaust,  mechanical, body, and aerodynamic.    Also, it refers to an auto condition code word used to specify a  restored or authentic original car requiring work to make it  roadworthy.sound(banging-1) - Sharp loud pounding or hammering sound produced in  the front end when braking or turning.  It is usually caused by a  strut rod with worn and/or torn bushings. sound(banging-2) - Sound produced when an engine backfires. sound(banging-3) - Sound produced when metal parts are too close to each  other.  If the sound comes from inside the engine, a serious problem  exists.sound(bell) - Bell-like or clanking sound produced when hitting a bump  in the road.  It is usually caused by a worn out shock absorber. sound(bumping-1) - Sound produced by a loose main bearing.  It makes a  deeper heavier sound than a connecting rod.  It is most audible when the  engine is lugging.  The sound can be isolated by shorting out spark  plugs. sound(bumping-2) - Sound produced by a starter motor when cranking.  It  is due to a loose pole shoe dragging against a turning armature.sound(bumping-intermittent) - Sound produced by a loose flywheel.  The  noise may tend to fade in and out.  Shorting out the spark plugs will  not effect the sound.  One way to isolate the problem is to turn the  ignition off, then back to ON position when the engine has just about  stopped.  This action induces a sudden twist to an engine and will  produce a noticeable knock if the flywheel is loose.sound(buzzing-high pitched) - Sound produced in an automatic  transmission due to a plugged filter.  Changing the filter and fluid  should cure the sound.sound(chattering-1) - Rapid rattling, clicking, vibrating sound produced  when a clutch plate is engaged.  Possible causes include: clutch plate  and pressure plate combination poor (most common); clutch plate facing  that is oily, greasy, glazed, worn, and/or warped; splines on clutch  plate hub or transmission shaft worn, broken, and/or loose; splined hub  binding; pressure plate binding; pressure plate release levers binding  or out of adjustment; pressure plate springs worn or wrong length;  clutch housing or clutch plate assembly out of alignment; universal  joints worn or loose; engine mounts worn, loose, broken, and/or soaked  with oil; drive axle or differential worn or loose; and bent  transmission input shaft.sound(chattering-2) - Sound produced when brakes are applied.  Possible  causes include: loose brake linings, brake drum scored or machined  poorly, brake shoes not centered, and warped brake drum and/or rotor.sound(chirping-1) - Short shrill sound similar to what birds make.  It  commonly occurs when a power steering fan belt gets a little loose and  will be heard when turning the steering wheel.  Another possibility is  a rear axle pinion bearing getting too dry.sound(chirping-2) - Sound produced in the front of a car by a water pump  whose bushings or bearings are starting to go out.  It will need to  replaced right away.sound(chirping-3) - Rapid sound produced by faulty EGR check valve.sound(chirping-4) - Sound produced by a faulty AIR or PAIR system.sound(chirping-5) - Sound produced in a car's front wheel area at higher  speeds that gets louder when turning the wheels one way and quieter the  other.  Possible causes include: wheel covers, cracked wheel, broken  wheel weld, noise generated at wheel-tire contact surface, faulty  suspension component(s), and faulty body component(s).sound(clanking) - See sound(bell).sound(clattering-1) - Sound produced in the front of an engine due to a  bad bearing in one of the belt-driven components.  Belts can be  removed one at a time to locate faulty component.sound(clattering-2) - Sound produced in the front of an engine due to  belt wear.  Sound is due to slipping and/or riding in the bottom of the  pulley groove.  Belt may be cracked, glazed, covered with oil or  grease, or worn unevenly.sound(clattering-3) - See sound(rattling-4).sound(clattering-4) - See sound(rattling-5)sound(clicking-1) - See sound(tapping-muffled). sound(clicking-2) - Slight sharp repetitive sound produced by a piston  with excessive wall clearance, a loose piston pin, or an old piston  with new tight piston pins.  An indicator of piston slap is a decrease  in engine noise as the engine warms up.  A loose piston pin will often  produce a click at the bottom and top of each stroke.  It is usually  loudest at idling speed, and becomes louder if the affected spark plug  is shorted out, or the timing advanced.  Tight pins will produce a  piston slap type sound that usually disappears after an engine is run  a few hundred miles and loosens up the piston pins.