Squealing noise silverado 2014 when she is shut down

[Jsdirt]

If it was leaking enough to make that sound, I'd bet the A/C would be non-op by now. Certainly possible though - could be a leaky high pressure blowoff valve.

 

A mechanic that's been around A/C will instantly pick up on the smell too - I would think the previous dealer that looked at it would have. It has a distinct smell to it from the oil when there's a large leak. If not, a refrigerant detector would definitely pick it up. There would also be a big oil spot wherever it was leaking from - dirt will stick to it, making it pretty obvious, especially on a truck that new.

[The Zip]

Read somewhere it may be a bad PCV O ring. Pull the PCV and see if the O ring is hard and brittle, if so, replace with a new ring. If not, this wasn't a costly investment, the ring should only be a hundred or so pennies.

[Jsdirt]

..... the ring should only be a hundred or so pennies.

 

As long as you don't buy it at any GM dealership ...

 

I bet that o-ring is $35 over there ...

[The Zip]

Point taken about the dealership. I shop at Rockauto, for six bucks you can get the entire valve. I would try this if this was happening to me, but what you don't want to do is spend a lot of money on an issue you haven't yet figured out. What happened with the dealer fix? As I think about it, this is a new truck. Only thing you will lose is being inconvenienced by taking it to the dealership, unless your bumper to bumper has expired.

 

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[Rush78]

I stopped by and they said as long as there is nothing lighting up, the truck is doing what it's supposed to be doing. The first time i noticed it she just came from an inspection, if there was anything out if wack i would think they would have picked up on it. That being said she is fully covered by warranty. So if i do notice something going wrong (loss of power, A/C, etc) i ll be bringing it in right away. Other than that they told me it would be a waste if it's not going to happen while there, because it would be impossible to trace without the noise.

When she goes back fir a semi annual I am going to be asking them to look into it again even if it's not happening.

There's no smell from the A/C and nothing appears to be leaking.

I have forwarded on the second video and asked exactly where the relief valve is that they are taking about. But i haven't heard back. I get off work Monday morning so I am thinking of swinging in on the way home to see if there is anything new they might have in it.

If it is the PCV valve causing this, shouldn't it be running for it to be making the noise? From what I understand it's creates a vacuum which when running you should hear a difference. This noise happens hours later, I have never heard it it immediately after i have shut the truck off from driving. With the exception of the other day when I heard it and it went, i started the truck for a second and shut it down. Noise was back. Please correct me if I am wrong, don't know much on it.

[The Zip]

If it is the PCV valve causing this, shouldn't it be running for it to be making the noise? From what I understand it's creates a vacuum which when running you should hear a difference. This noise happens hours later, I have never heard it it immediately after i have shut the truck off from driving. With the exception of the other day when I heard it and it went, i started the truck for a second and shut it down. Noise was back. Please correct me if I am wrong, don't know much on it.

 

The short of the PCV valve, handles venting pressure into the atmosphere. It doesn't run, just a static component. A failed PCV valve can cause noise in the form of a whistle or whine. Don't know if you can find the PCV valve but the easiest way to see if it's the problem is to temporarily block the vacuum source to the PCV valve and see if the noise changes or goes away.

[The Zip]

I stopped by and they said as long as there is nothing lighting up, the truck is doing what it's supposed to be doing. The first time i noticed it she just came from an inspection, if there was anything out if wack i would think they would have picked up on it.

 

Regardless if a light is on or not, there is some air audibly venting. Normal for a vehicle to vent, but to hear it there must be a defect somewhere with either the component or a piece supporting the component such as an O ring or grommet (using the PCV valve as an example, may be something else). Go to an auto parts store and ask the tech to show you where the PCV valve is located, spend about 6 bucks and change it out. This might fix your problem versus waiting for a light to come on.

[Jsdirt]

Can't be the PCV. Once you shut the engine down, the vacuum or pressure there stops.

[Rush78]

Ran into a mechanic there today who told me two things I can try the next time I hear the noise. 1) take off the gas tank fill cover, if it stops there could be a problem with the evap system. 2) take off the oil cover, if this stops it then it's the PVC valve.

Still going to swing into Hickman motors on my why home from work in the morning. Going to bring up the PVC to them and ask to speak to the mechanic who said he has the same problem.

[Rush78]

The idea of the PVC not working correctly is that there could be unburned fumes venting from the crank case. This could also cause the oil to go dirty or sluggish, from what i read somewhere.

[The Zip]

Ran into a mechanic there today who told me two things I can try the next time I hear the noise. 1) take off the gas tank fill cover, if it stops there could be a problem with the evap system. 2) take off the oil cover, if this stops it then it's the PVC valve.

Both of these would have something to do with venting, good recommendation, give it a shot

 

 

Can't be the PCV. Once you shut the engine down, the vacuum or pressure there stops.

With normal operating components I would agree, but Rush has some component that has failed or is failing and the pressure is not venting correctly.

[Jsdirt]

The idea of the PVC not working correctly is that there could be unburned fumes venting from the crank case. This could also cause the oil to go dirty or sluggish, from what i read somewhere.

 

I've got a '00 4.3 in a '89 S10 Blazer with no PCV system at all - oil stays nice and clean, FWIW.

 

 

 

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With normal operating components I would agree, but Rush has some component that has failed or is failing and the pressure is not venting correctly.

The pressure would bleed past the rings, and on the cylinders with open valves, into the intake by the time you got out of the truck after shutting it down. Highly doubt it's the PCV system causing the sound based on that fact.