Whinning noise Yukon 2013

TruckME

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Hi everyone,

So my truck - 2013 Yukon 6.2L - has been making this whinning/whistling sound.


Have had the sound for a few month now. It usually appears after driving it for some time and you hear it only when I accelerate at lower speeds (maybe it is there at higher speeds too but I can't hear it anymore)

I have taken it three times to the dealer and they are not able to tell me what it is. There is no performance issue which is a good sign apparently. Their last comment was, it may be something wrong with the transmission (and something else)

What I know it that it is not the pulleys or the steering pump. It sounds like there is an air leak but the dealer told me if there was a lead they would have detected it and they would be able to read the code with their scan tool.

Appreciate your comments.

Thanka
 

dnt1010

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Kind of a random guess here but does the 2013 have the flapper adaptive valve in the exhaust pipe? I think it may have been a 2014 addition but if you have one just clamp it open temporarily and see if the sound goes away....
 

Doubeleive

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Kind of a random guess here but does the 2013 have the flapper adaptive valve in the exhaust pipe? I think it may have been a 2014 addition but if you have one just clamp it open temporarily and see if the sound goes away....
NO
 

Doubeleive

Wes
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Hi everyone,

So my truck - 2013 Yukon 6.2L - has been making this whinning/whistling sound.


Have had the sound for a few month now. It usually appears after driving it for some time and you hear it only when I accelerate at lower speeds (maybe it is there at higher speeds too but I can't hear it anymore)

I have taken it three times to the dealer and they are not able to tell me what it is. There is no performance issue which is a good sign apparently. Their last comment was, it may be something wrong with the transmission (and something else)

What I know it that it is not the pulleys or the steering pump. It sounds like there is an air leak but the dealer told me if there was a lead they would have detected it and they would be able to read the code with their scan tool.

Appreciate your comments.

Thanka
how did you determine that it is not the pulleys or power steering pump? did you take the belts (including ac pump belt) off and it still makes the sound?
if so then it is possibly something in the intake or maybe the harmonic balancer.
Sounds like it is RPM dependent,
does it do it in gear while driving?
in neutral?
does it do it if the brake pedal is applied?
you might need a helper and a mechanics stethoscope or a set of chassis ears to try and pin it down
my guess is it is air or fluid related, try taking the intake apart clean it and the throttle body and a new air filter, put it all back on snug and see if that makes any difference
 
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TruckME

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how did you determine that it is not the pulleys or power steering pump? did you take the belts (including ac pump belt) off and it still makes the sound?
if so then it is possibly something in the intake or maybe the harmonic balancer.
Sounds like it is RPM dependent,
does it do it in gear while driving?
in neutral?
does it do it if the brake pedal is applied?
you might need a helper and a mechanics stethoscope or a set of chassis ears to try and pin it down
my guess is it is air or fluid related, try taking the intake apart clean it and the throttle body and a new air filter, put it all back on snug and see if that makes any difference

I had specifically asked the dealer/mechanic to check the pulleys and the power steering pump. My first guess was there is something wrong with the pulleys because my serpentine belt had broken before because of a bad pulley tensioner which was replaced later. That was six month before the whining noise issue had started. But I will have it rechecked with another mechanic.

And yes it is RPM dependent. You hear it in both gear and neutral if you apply the accelerator. Once you take off your foot from the accelerator the sounds winds off after like 2-3 seconds. If you apply brake it does stop but so does it if you don't accelerate.

Yeah I think I will do the intake and throttle body cleaning. Any advice on the throttle body cleaning. I have seen videos on youtube where guys have messed up the the cleaning and the throttle body had to be re-programmed again. Other just apply the spray and wipe the dirt off and it works without an issue. I hope it is not the harmonic balancer. My truck just crossed the 100k mark but yeah it is nine years old.

Thanks again for your comments.
 

Doubeleive

Wes
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I had specifically asked the dealer/mechanic to check the pulleys and the power steering pump. My first guess was there is something wrong with the pulleys because my serpentine belt had broken before because of a bad pulley tensioner which was replaced later. That was six month before the whining noise issue had started. But I will have it rechecked with another mechanic.

And yes it is RPM dependent. You hear it in both gear and neutral if you apply the accelerator. Once you take off your foot from the accelerator the sounds winds off after like 2-3 seconds. If you apply brake it does stop but so does it if you don't accelerate.

Yeah I think I will do the intake and throttle body cleaning. Any advice on the throttle body cleaning. I have seen videos on youtube where guys have messed up the the cleaning and the throttle body had to be re-programmed again. Other just apply the spray and wipe the dirt off and it works without an issue. I hope it is not the harmonic balancer. My truck just crossed the 100k mark but yeah it is nine years old.

Thanks again for your comments.
I guess I meant if you are in neutral and hold the brake pedal or press the brake while hitting the gas pedal see if it stops making the noise or not, could be a vacuum noise, leak, master cylinder.
those were just some suggestions off the top of my head to try and narrow it down to maybe one particular thing.
as far as cleaning the intake you can just grab a can of throttle body cleaner and some kind of rag that won't leave any lint or anything behind, you can just spray and wipe, just don't push ******* the throttle butterfly just hold it up, I have cleaned mine (in multiple vehicles) I don't even know how many times and never had a single issue.
 
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TruckME

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I guess I meant if you are in neutral and hold the brake pedal or press the brake while hitting the gas pedal see if it stops making the noise or not, could be a vacuum noise, leak, master cylinder.
I did that but the noise is still there.
Will do the throttle body cleaning and change the air filter then. Thanks for the suggestions. I hope this will fix it.
 
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TruckME

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Some more updates, today the engine switched off on its own when I had stopped at the red lights. It turned on again but I am not sure what the issue is. I also noticed that the steering and the gas pedal had gone soft. If it is the intake not sure why the steering wheel went soft. What could it be?
 

swathdiver

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Sounded like a pulley or tensioner to me. A vacuum leak it could also be and if really bad, would cause the engine to stall. Do you have a scan tool to view your Long Term Fuel Trims?
 

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