That was what I also mentioned earlier, as this sound is not the normal hydraulic lifter tick, but more of an onset. However it definitely is coming within the motor, I will get another clip when possible. This is what I recorded this morning during warmup when it starts, and was about 3-4 min into the warmup.
Audio is not great but the inconsistent tap makes me think it's just the smallest amount of excess lash showing it's face.
I agree, but there is noticeable wear within the radial axis....
MAYBE, now this is only a wild theory, but given the excess play on the #8 exhaust rocker which will be swapped this week, this total play might have taken up just enough lifter preload to allow for this light tick. The preload changes (lash opens) when an aluminmum block gets hot, on average by .012" and GM really only aims for about .050" of preload with these lifters.
I agree this sounds like an internal lifter issue, either with bore wear, bleed down, whatever, but a chance on a $12 rocker is worth it before pulling a head.
The fact I have at least .030" of play on that #8 rocker, and the noise is coming from #8, I'm hoping this will be the fix but not betting the farm.
@Dustin Jackson The noise is louder from below but I would think since this is where the initial contact is being made that it makes sense. With a stethoscope, you can hear what sounds like a rattling clatter of likely the rocker arm in the valve cover bolt.
Edit to add...if the lifter is bad, it makes sense you would hear clatter in the rocker also.