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Old 26th July 2006, 11:08   #1
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Default What's that sound?

I found this interesting article at PM (Popular Mechanics)

A moving car is a complex symphony of sound, most of it reassuring--tires humming, engine rumbling, tailpipes roaring. But every now and then a dissonant note creeps into the mix--and the alert driver's ears prick up: Did you hear that? Here's a guide that identifies those oddball sounds and helps you sort out which conditions you can let slide and which ones mean repairs--and how fast you need to make them.

WHERE: From one or more tires.
WHEN: At low speeds, especially in the morning. Speeds up with car.
WHAT: Flat-spotted tire. As the tire rotates the flat spot thumps on the ground. Nylon-cord tires will flat-spot overnight and make this sound until they warm up. Itís usually worse in colder weather. You can permanently flat-spot the tires by locking up the wheels, grinding massive amounts of rubber off the tread in one spot.
FIX: Replace your nylon tires with steel-belted tires. If youíve ground down your tires like a pencil eraser, you can either live with the vibration until wear reduces the flat-spotting or buy new tires.

FFFFffff ttttFFFF ffff ttttFFFFffff tttt
WHERE: Under the hood.
WHEN: Most noticeable at idle.
WHAT: An exhaust manifold gasket has failed, venting hot exhaust gases to the air.
URGENCY: Itís not getting better on its own. The blowtorch of corrosive gases will eventually damage the manifold. Oh, by the way: Carbon monoxide from the leak may make you drowsy or dead.
FIX: Replace the exhaust manifold gasket before the leak eats a hole in the manifold.

WHERE: Under the center of the car, toward the rear.
WHEN: While in motion and varying with road speed.
WHAT: U-joint (rwd or 4wd only). A U-joint in your driveshaft has finally run out of grease, is getting loose and is about to fail.
URGENCY: Thatís really just an urban legend about cars polevaulting over broken driveshafts when U-joints fail at speed, right?
FIX: Replace all the U-joints and keep the new ones greased regularly.

WHERE: Inside the wheels.
WHEN: Slowing down; itís sometimes worse on damp days.
WHAT: Your brake pads are stroking the discs like a violin bow.
URGENCY: Sometimes they do that. Your brakes still work fine.
FIX: Try new pads, adhesive to hold pads to the piston or shims to insulate the piston from the pads. Another option: earplugs. (Sometimes the sound is difficult to eliminate.)

WHERE: Under the hood.
WHEN: Anytime the engine is running, but itís most noticeable at idle speed.
WHAT: Vacuum leak. A rubber or plastic vacuum line or fitting has split or fallen apart.
URGENCY: If youíre wondering why your Check Engine light is on and why your car idles poorly, this is probably why.
FIX: Reconnect or replace the line.

WHERE: Under the center of the car or truck, near the middle.
WHEN: Starting off at traffic lights. Most often heard on pickups with automatic transmissions, not manuals.
WHAT: The splines that allow the driveshaft to change length where it connects to the tailshaft are binding as you slow down and then releasing when you start off.
URGENCY: Annoying, but They All Do That--or at least some of them do it some of the time.
FIX: Packing the spline area with special grease helps for a month or so. Or just sell the car or truck.

WHERE: One or both front corners of the vehicle.
WHEN: Going around slow, sharp corners under light throttle.
WHAT: A CV joint that allows your front wheels to turn and still be powered is loose. The boot has failed and let out all the CV jointís grease, or maybe itís just time for it to wear out.
URGENCY: Donít leave town. Donít use a lot of throttle around sharp turns. Your car will stop suddenly when the joint completely fails.
FIX: Replace the entire off ending half-axle.

WHERE: Front end.
WHEN: Initially, when parking; eventually, over small bumps.
WHAT: The ball joint that connects the suspension arm to the upright has lost its lubrication and the metal-to-metal contact is wearing it out.
URGENCY: Make an appointment. Avoid bumpy roads, curbs and potholes.
FIX: Replace the ball joint.

WHERE: Front of the car.
WHEN: At idle. (Check for weeping coolant at the bottom of the water pump, too.)
WHAT: Water pump bearings.
URGENCY: When the bearings fail completely, the fan will pull forward and slice a nice big smile-shaped chunk out of the radiator, making it leak profusely.
FIX: You need a new pump.

WHERE: Under the hood. WHEN: Whenever you rotate the steering wheel all the way to the left or right steering stop and hold it there.
WHAT: The pressure relief valve inside the pump is dumping excess power-steering hydraulic fluid back into the reservoir. Itís supposed to do that, although maybe a little more quietly.
URGENCY: No big deal.
FIX: Itís normal. Actually, you should check the level of powersteering fluid in the pump. Donít hold the wheel hard on the stop like that; it annoys pedestrians and is tough on the belt.

WHERE: Under the hood.
WHEN: Right after startup until you rev the throttle a couple of times and the rubber warms up.
WHAT: Belt squeal. A loose or glazed belt, bad tensioner or misaligned pulley.
URGENCY: Make an appointment, and donít take a long trip. This wonít go away on its own--until just before the belt fails.
FIX: Check belt tension and pulley alignment; replace the belt.
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Old 26th July 2006, 22:57   #2
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Thats an excellent article .......keep sharing....

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Old 27th July 2006, 20:47   #3
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Some more:

Peeeeeeeeee... (continuous high pitched whine)
WHERE: Somewhere towards the back of the car (hard to localize)
WHEN: While the ignition is at the "engine on" position. Sound may stop momentarily if the engine is not running and the key is still in the "engine on" position, noted before starting the car.
WHAT: Fuel Pump (inside the petrol tank usually under the rear seat)
URGENCY: Depends on the make and model of your car. Some cars just do this, but if you have never heard it before and it has started recently, it could be your fuel pump planning for its retirement.
FIX: Get the fuel pump overhauled, replace fuel filter.

Tap tap tap tap... tap tap...
WHERE: From behind the car towards the center, mostly heard in hatchbacks
WHEN: While driving at high speeds / over uneven roads
WHAT: Rear numberplate fixed only at the top with a gap at the bottom
URGENCY: Slight risk of wearing out the paint below the plate, high risk of driving yourself crazy!
FIX: Wedge some thermocol into the gap at the bottom of the plate.
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Old 30th July 2006, 11:10   #4
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good one guys..thanks for sharing..
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Old 30th July 2006, 20:34   #5
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Superb article. Thanks for sharing.
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Old 1st August 2006, 15:12   #6
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WHERE: From the back seat. Sparks fly, noise grows louder after each rev
WHAT: The wife. In disagreement over n matters (about the money spent on ICE for e.g)
URGENCY : Immediate pitstop, change the wife or change the car, before u have to ram a bus and then change ur car.

Last edited by esteem_lover : 1st August 2006 at 15:15.
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Old 19th August 2006, 12:42   #7
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Dude thanks alot, i was getting this knocking sound from the front of the car (only heard inside) and the mech kept on fleasing me saying to change my suspension kit and sound kept on coming back
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Old 19th August 2006, 14:25   #8
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Where - Front tyres
When - at parking speeds
What - congrats, you've just run over a big pile of cow dump.

PS : For Indian drivers only. LOL

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Old 25th August 2006, 04:25   #9
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Originally Posted by Shan2nu
Where - Front tyres
When - at parking speeds
What - congrats, you've just run over a big pile of cow dump.

PS : For Indian drivers only. LOL

have heard this sound pretty often....
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Old 29th August 2006, 11:35   #10
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Ghooooon ghooooon
where : From the front, under bonnet
When: Mid-high revvs, sound is less when AC is on
Problem : AC compressor bearing is toast
Urgency : Get it fixed at the next service
Fix : Replacement of compressor bearings and compressor overhaul. Takes two days sometimes as the compressor is sent to Subros etc., Cost close to 6-8K even in economical cars.

where : From the front, under bonnet
When : Cold/humid starts
Problem : Belt is loose
Urgency : NADA
Fix : Belt tightning

taptaptaptaptap or karkarkarkarkar
When : idling
Problem : tappet noise
Urgency : medium
Fix : Tappet adjustment or replacement depending upon what gives.

hope this helps (Note : These are from personal expiriences)
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Old 18th September 2006, 20:39   #11
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Hi Guys
I have an yr old getz and when i aprk it after driving it,i can hear sound coming from underneath the car,more on front side than rear though cant localize it precisely.If i remember correctly,sound has been there since i bought it and i never told sevice guys about it though 3rd service is due in 3 weeks.

Sound is like if small stone is thrown on concrete and can hear after 1-2 min of switching off till about 20 min.Its very irregular and comes in interval of 2-3 seconds.

sound is more like what four_tire has said in his post below though my driving habits r not bad...

WHERE: Front end.
WHEN: Initially, when parking; eventually, over small bumps.
WHAT: The ball joint that connects the suspension arm to the upright has lost its lubrication and the metal-to-metal contact is wearing it out.
URGENCY: Make an appointment. Avoid bumpy roads, curbs and potholes.
FIX: Replace the ball joint.
I am more of ICE man and dont know much abt engine-vengine,so i am sorry if its a stupid question.

Last edited by rsjaurr : 18th September 2006 at 20:42.
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Old 23rd September 2006, 18:33   #12
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no answer yet!
guys,did i post in wrong thread or do i have to start a new thread?

Thanx in advance........
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Old 10th October 2006, 22:09   #13
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well...let me 1st say thank you guys for ur support!

I went to Hyundai service centre for 3rd service of my Getz and asked the service guy about same problem.He told me that car has some heat/cooling sensors in the exhaust system and so after driveing it sensors r activated to cool it down,so its not a problem.That was enough for me and dint ask him any other question.

Last edited by rsjaurr : 10th October 2006 at 22:13.
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Old 12th October 2006, 10:44   #14
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My 7-year old M800 makes some sqeaking noise whenever the accel is pressed;
Noticed it when I am warming up the engine in the morning.
Though the sqeaking noise is not loud enough, it seems to spell trouble
What's that sound ?

From: somewhere below the car.
When: whenever accelerator pressed while warming up the car in the morning.
Reason: <dunno. asking the same>
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Old 25th October 2006, 22:47   #15
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Hahaha thats great , i would love to elaborate on the acoustic variations depending on the type of poop but will refrain.. from fear of being permanently banned from the forums !!!

Last edited by NikN : 25th October 2006 at 22:51.
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