unusual whistle when letting off gas

[BigRobRN]

Could this be the death whistle of bad head gaskets?
My truck is an 06 with 87k miles.
S&B intake, 4" MBRP TB exhaust, SCT Xcal 2 with street tune currently.

It doesn't make the sound when accelerating, only when letting off the gas. I noticed it tonight after getting to 80mph quickly and then coasting back down to about 60. It made this unusual, low pitched whistle. It was obvious, but it wasn't a high pitched whistle by any means.

I don't tow often at all and I drive fairly conservative. No racing, but I do like to get to my crusing speed a little quicker than most.
I'm not puking coolant, not using coolant. I do blow some white smoke on cold mornings when I first crank her up to warm, but when I put it in drive and start going, NO smoke.

Should I have a dealership check it out?
Can this be repaired under warranty?

[Boggsie05]

Subscribed ! - Exactly same issue to me tonight

[07stroker]

Is it kinda like a tea kettle whistle?

[Fireman5606]

Mine has been making a similar noise since the weather has turned colder. It is not a high pitched noise, more of a low drone. i am thinkin it may have something to do with the turbo speed when you decelarate and the air temperature. I also don't have any coolant leaks, oil or coolant missing.

[Tyler]

Hmm... I've heard of this before on here and I think it turned out to be turbo flutter... but not sure. Hopefully someone with knowledge will show up.

[BigRobRN]

Originally Posted by 07stroker

Is it kinda like a tea kettle whistle?

Honestly its been years since I've heard an actual tea kettle. But I'm thinking of water boiling in an old pot and hearing the loud high pitched whistle through the steam escape hole.
NO, it does not sound like that. Its a fairly obvious LOW pitched whistle when letting off the accelerator. I can't hear anything when accelerating accept the turbo spooling, the engine, and the exhaust.

Sure hope its not the darn headgaskets. I bought this truck back in November and have only put 3k miles on it. It did come with the S&B intake and the TB exhaust. Its mostly my weekend truck.

Do I need to listen for a whistle at the degas cap after driving for a while, stopping and killing the engine and lifting the hood?

[BigRobRN]

anyone else care to chime in?
anything else to look for, check for?

[SCUFFY828]

loosen the radiator cap , dont take it off just loosen it so it cant buld pressure , and see what it does , if it doesnt do it with cap loose , replace the cap, just because it whisltles from the cap doesnt mean its headgaskets , caps are known to go bad as well, that is the same ****y cap they have been using on every car for awhile , in my opinion they should have designed a better one for these trucks

[Big Mule]

Mine has been making a similar noise since the weather has turned colder. It is not a high pitched noise, more of a low drone. i am thinkin it may have something to do with the turbo speed when you decelarate and the air temperature. I also don't have any coolant leaks, oil or coolant missing.
_______________
Exact same thing he said.

[BigRobRN]

As soon as I got home today and turned my truck off I stuck my ear next to my degas bottle cap and I can hear pressure escaping.

Do I have a serious problem?