⚠️ Do Not use heavy oil. More so in "Winter" where engine gets below 32°F or more when parked.
See my Cave,
Oil and FilterRun a few sec w/o oil pressure generally won't cause lifter noise and if does then should go "quiet" very fast. And when does this, This will kept happening every time you parked overnight or longer.
Lifter noise is often problem(s) w/ iffy lifters, worn parts, or bad adjustment.
Valve rockers on Hydro lifters need 0 or very close to 0 so hydro has 0 play or is Very slightly compress all the time
when engine warms to op temp.This is Why Intake and Exhaust valves often have different lash on a cold engine because E side valves get hotter and sooner.
So May just need "Fiero" V6 and others to run long enough to reach normal op temp to silence the valve train.
Even then just having change the oil and doing other work, can "wash" crap out oil "pipes" and lifters can take a long time or never get quiet that's if really was quiet to start but didn't bother you.
Most people have no clue how much crap is in the engine even if oil was change 3,000 - 5,000mi after 50,000mi yet alone 100,000mi driving...
Note: Lifters have a Clip on top to keep parts together. This chip doesn't like to be beaten w/ bad adjustment etc. and can fail.
But "dirt" in a lifter can cause same noise as iffy adjustment or wear problems because inner parts won't move right and act like system w/ too much valve lash.
I recently replace lifters on a Duke w/ no valve adjustment allowed and that was night/day difference on noise. Old lifters had varnish and dirt causing lifter binding and while often can clean that, no time to do it for all lifters. You can't just pop the clip etc or very likely to loose very small parts. If binding have to let carb cleaner etc to work into the parts just to get inner piston out w/o damage. Is harder to work on Roller lifters too because roller tip wants to roll when trying to remove/install the top clip.
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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)
The Ogre's Fiero Cave