[77-C10]

Is anyone able to possibly assist me with the sound and right direction to remedying it.
https://drive.google.com/file/d/1Ua4qLHWWxs7iG0ylUxGW1v_Es3aQPWaH/view?usp=drivesdk

 

[Blue Goose]

Take the belt off and try without it.Still there get ready for motor swap

 

[Steven Snyder]

Try using an socket extension as a stethoscope to pin point that noise. CAREFULLY place one end of the extension on each piece of equipment that is on your serpentine system, while the other end of the extension is on your ear. You should be able to hear each piece with their distinctive sound. The one that is extremely loud will stand out. Possible a bearing going out in one of the pieces of equipment. But be VERY CAREFUL when doing this with the motor running. Good luck.

 

[w1ck3d0n31966]

Noiwe under hood

Sounds like a bearing noise put your 2 fingers on the alternator while your truck is running it may be it

 

[TireSmoker]

how long has it been doing this? any issues with oil pressure, how many miles on this engine?fahne19

 

[77-C10]

Thanks for all the replies! Just an update for y'all,

Blue Goose: I went ahead and took the belt off and ran it for a moment but no luck with it stopping.

Steven Snyder: I didn't get that far as it seems to be going on with no other accessories running. I'm starting to wonder if it is a issue with the crankshaft pulley.

Lilwicked: Sound was still there with no belt on it so it has been checked off the list for now.

TireSmoker: I just got the truck from an auction and it has made that sound since we got the truck running after swapping the battery out. It may be having trouble with oil pressure as nothing ever makes its way to the valve cover area when running. The odometer reads at ~240k if I remember correctly. (Lord only knows if it's accurate)

 

[wingnut1962]

that sure sounds like an exhaust whistle..... but listening to it on the computer can be very deceptive. you say it makes the sound with all belts off?

 

[wingnut1962]

that sure sounds like an exhaust whistle..... but listening to it on the computer can be very deceptive. you say it makes the sound with all belts off?

As I cannot tell where its coming from, does it sound like its coming from the torque converter area by chance?

 

[Blue Goose]

drain the oil and look for metal shavings.sure sounds like a scorched main or rod bearing to me

 

[Fussy&Grumpy]

A quick and dirty method of locating noises is to purchase a mechanic stethoscope and toss away the end of it. Then grab a length of 5/16" brake line (mine has a piece 28" long) and stuff that into the end of the tubing. With this, you can CAREFULLY listen for air leaks, noises and such without getting yourself too close to moving or hot parts. I converted my old stethoscope from my days as a paramedic into this.
.
As for the engine noise in the video, spray some WD40 on to the top of the intake. Go gradually at first and monitor if the noise changes or the engine idle increases noticeably. Then if all looks fine, use water on the exhaust manifolds to note if there is any exhaust leaking out.
I am estimating this is an LS-based engine, and with the mileage being unknown, I would recommend replacing the engine oil pump and pickup seal.
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I worked for a company that had over 250 Chevys and GMCs with these engines and you could almost set your watch by the odometer and when they required this maintenance. This issue is normally misdiagnosed as a faulty oil pressure gauge sending unit.

 

[77-C10]

Finally have located the issue, after moving homes and not having as much time as I wanted to work on the trucks it took a bit.
It has been the crankshaft the whole time making the sound.
Thanks to everyone who had helped point me in the directions that led to finding it.