01 Tahoe 5.3 tick then goes away

[Doubeleive]

unfortunately sounds less like lifter tick and more like rod knock to me.
my 03 has had lifter tick for years and years and the sound is not the same on yours
a lifter tick will sound more external and near the top, yours sounds more internal and deeper sounding
just my opinion, I would spend the $35 and send a oil sample out to blackstone labs and see what shows up.

 

[SnowDrifter]

When you say,
"It's normal for it to sound like a ticking lifter."
Is the evap purge solenoid capable of ticking at the same pace as a ticking lifter?

Yup

Threw me for a loop shortly after I got my rig.

Sounds like a ticking lifter at idle. Roughly the proper cadence. When revved, accessory noise drowns it out. Then it 'comes back' when idle is resumed.

 

[Marky Dissod]

Interesting. My guess in an apparently similar situation would be an exhaust manifold leak. Hmmm ...

 

[SnowDrifter]

All things worth checking

Got a chance to watch the video with some better speakers.

Honestly, sounds almost like some gnarly piston slap to me.

Real easy way to isolate if it's rod knock vs. anything else: Go to the parts store, grab the cheapest 20w50 they have and throw that in there for a quick 5 minute test.

If it's rod knock, the thicker oil will quiet it down. Will help to cushion the faulting tolerances.

If it's piston slap, will get louder. Thicker oil doesn't sling as well to the piston walls.

Wrist pin/lifters? Not sure.

Exhaust leak: no change


Don't drive the car around with the thick oil in it. Oil pump, drainback, etc ain't rated for it. This is just for a quick driveway test.

 

[OR VietVet]

I have to agree with @Doubeleive. That noise does sound lower in the engine. Mechanic's stethoscope would help pinpoint the noise.