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Old 23rd July 2010, 01:53   #1
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Exclamation Whining sound from throttle body in My Spark

Hi All,

Have a chevy spark. Recently noticed that when the engine is OFF and the ignition is in ON position, there is a constant whining noise(annoying) from the throttle body.

1) Has anyone noticed such a noise in their cars?
2) Is this part of the normal functioning of the TB?
3) How can we eliminate/reduce this sound?
4) Is there any other checks to be done before blaming the TB?

Experts, countrymen and friends - help my ears !!!
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Old 23rd July 2010, 07:46   #2
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When the ignition is switched on and engine not started, the fuel pump comes on - the noise is a whining type but this goes off after 3-4 secs when the required pressure is reached.

Is this what you're talking about?
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Old 23rd July 2010, 10:04   #3
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Quote:
Originally Posted by vigsom View Post
When the ignition is switched on and engine not started, the fuel pump comes on - the noise is a whining type but this goes off after 3-4 secs when the required pressure is reached.

Is this what you're talking about?
Nope Som, I checked carefully and the sound is from the throttle body itself. Checked today morning and here are the findings.

1) Whining does not stop even after 5 minute when engine is OFF, Ignition is ON
2) When you turn off ignition, the throttle body makes a clak, clak sound (like self adjusting) and then go dead silent.
3) The whining sound remains but is not audible when the engine is running.
4) The whining seems to be there only when the actuator position is at Idle. At any open or full open state, the sound seems to die off.
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Old 23rd July 2010, 13:20   #4
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My cousin is also facing the same problem. Service center techs, not able to explain this (suspects the PW motor).
They says, need a through check up
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Old 23rd July 2010, 17:34   #5
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Well I have been searching high and low for this issues resolution. Many forums point out that this may be due to an air intake valve leak inside the throttle body.

The resolution they suggest are too risky to try(will void warranty too). Open the throttle body, sand down the uneven surfaces and reposition the valve.

If anybody had experience this issue and resolved it may be able to shed more light.
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Old 23rd July 2010, 17:45   #6
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It should be the sound from the radiator fan. As per your description it can be it. Normal.
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Old 23rd July 2010, 18:01   #7
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Quote:
Originally Posted by electricheart View Post
I checked carefully and the sound is from the throttle body itself.
1) Whining does not stop even after 5 minute when engine is OFF, Ignition is ON
2) When you turn off ignition, the throttle body makes a clak, clak sound (like self adjusting) and then go dead silent.
3) The whining sound remains but is not audible when the engine is running.
4) The whining seems to be there only when the actuator position is at Idle. At any open or full open state, the sound seems to die off.
Hi, if its indeed the throttle-body from which the whine is emanating, it could be the idle-air-control-valve, usually a stepper motor that controls a valve depending on coolant temperature (also whether the A/C is on or off). Its surprising that you're able to hear the whine, this motor is rather tiny & very silent in its operation. Is your temp-gauge working fine or is it fluctuating also ?

Quote:
Originally Posted by electricheart View Post
Many forums point out that this may be due to an air intake valve leak inside the throttle body. The resolution they suggest are too risky to try(will void warranty too). Open the throttle body, sand down the uneven surfaces and reposition the valve.
With your engine off, there's no air-flow within the throttle-body, 'am unable to understand how a leak could result in the whine you're hearing.

You could probably try suggesting to the GM service center guys to have your IACV checked, swap it with a new one to see if the whine persists.

Does your Spark have a drive-by-wire throttle (?), in which case it could be the motor for the throttle-butterfly.
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Old 23rd July 2010, 18:18   #8
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Quote:
Originally Posted by electricheart View Post
Many forums point out that this may be due to an air intake valve leak inside the throttle body.
.
This cannot happen as the induction process starts only after you start the engine. The sound most likely (90%) is from your auxiliary fuel pump. Only fuel pumps make that"whining" type of a sound. The other 10% could be some electrical short circuit. Could be a faulty TPS if you are 100% sure its coming from inside the throttle body. Small motors do not make a "whining" noise so you can isolate that unless you are mistaking a buzzing noise for a whining one.

p.s: If you can grab hold of a stethoscope, plug one into your ears and pin point the culprit. I have seen F1 folks do this to listen to minute undesired noises before they ok the critical assembly.

Last edited by The Wolf : 23rd July 2010 at 18:22.
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Old 23rd July 2010, 18:42   #9
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Thanks for all you inputs and thoughts!

Quote:
Originally Posted by im_srini View Post
Hi, if its indeed the throttle-body from which the whine is emanating, it could be the idle-air-control-valve, usually a stepper motor that controls a valve depending on coolant temperature (also whether the A/C is on or off). Its surprising that you're able to hear the whine, this motor is rather tiny & very silent in its operation. Is your temp-gauge working fine or is it fluctuating also ?

Does your Spark have a drive-by-wire throttle (?), in which case it could be the motor for the throttle-butterfly.
My spark is just few weeks old, and I am not sure if it has a drive-by-wire throttle mechanism. The temperature gauge is a digital one in my spark and has not shown any erratic behaviors yet.

Your point regarding the idle-air-control-valve seems to be a good start point for isolating the root cause.

Quote:
Originally Posted by The Wolf View Post
Could be a faulty TPS if you are 100% sure its coming from inside the throttle body. Small motors do not make a "whining" noise so you can isolate that unless you are mistaking a buzzing noise for a whining one.
I am very positive that the sound is from the throttle body. I had my ears on the TB to isolate the sound. It is a very audible whining sound when the engine is OFF and the ignition is ON.
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Old 25th July 2010, 10:14   #10
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Quote:
Originally Posted by electricheart View Post
My spark is just few weeks old, and I am not sure if it has a drive-by-wire throttle mechanism
AFAIK,the Spark uses an accelerator cable to drive the Throttle Body actuator

Can you check if this whine is felt on other Sparks as well?
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Old 25th July 2010, 20:49   #11
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Quote:
Originally Posted by vigsom View Post
AFAIK,the Spark uses an accelerator cable to drive the Throttle Body actuator

Can you check if this whine is felt on other Sparks as well?
Thanks for clarifying that Som. I am taking the car for service this week and will be sure to check other Spark's for the whining.
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Old 26th July 2010, 21:53   #12
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Almost all car uses cable.

Pop the hood. Put the key on ACC. Now with a finger try pulling the accelerator cable on the throttle body. See if the sound changes.

Normally whine sound is from electronic fuel pump.
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Old 28th July 2010, 03:22   #13
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Quote:
Originally Posted by SirAlec View Post
Almost all car uses cable.

Pop the hood. Put the key on ACC. Now with a finger try pulling the accelerator cable on the throttle body. See if the sound changes.

Normally whine sound is from electronic fuel pump.
Checked this and the result is:

Key in ACC position: Loud Whining

When Accelerator cable pulled - sound reduces and keeps increasing based on the amount of throttle opened.

I am not sure, but I believe the sound remains even when the engine is running.
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Old 28th July 2010, 15:49   #14
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Default 1000 KM Service - DONE !

Had my courtesy 1000 KM service done today morning.

The service adviser says that all Spark and U-VA will make this whining sound and will have a slight accelerator pedal feedback pull. This is by design for the specific throttle body in these cars. Any one to second this point?

Trident did a priority service for me. Drove in at 10:00 AM, Drove out at 12:30 PM.

Full wash, Electrical check, Body check, Engine oil & Filter replacement (paid by me), Under body nut/bolt tightening, Alignment check, Lubrication of doors & gear linkage etc. finished in just 2.5 Hrs and car delivered back to me. Felt nice to be watching what is going on.
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Old 27th December 2013, 13:22   #15
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Default Re: 1000 KM Service - DONE !

Quote:
Originally Posted by electricheart View Post
Had my courtesy 1000 KM service done today morning.

The service adviser says that all Spark and U-VA will make this whining sound and will have a slight accelerator pedal feedback pull. This is by design for the specific throttle body in these cars. Any one to second this point?

Trident did a priority service for me. Drove in at 10:00 AM, Drove out at 12:30 PM.

Full wash, Electrical check, Body check, Engine oil & Filter replacement (paid by me), Under body nut/bolt tightening, Alignment check, Lubrication of doors & gear linkage etc. finished in just 2.5 Hrs and car delivered back to me. Felt nice to be watching what is going on.

Do you still have the same issue on the Spark ? I have it too. One thing I noticed is the FE is very bad and nowhere near what GM promises. I get only 10-11. What about you ?
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