I have the 2016 5.3LT engine in a Jeep Wrangler. It makes the noise and my guess is oil drainback. Might be the oil filter. I used a Mobil1 filter which may be a POS. Have to change my Amsoil oil again ?, engine ran too rich on startup for 1/2 tank, so will use and stay with NAPA Gold or Wix (same filters and aircraft quality) from now on. Tell AC Delco to shove their junk filters up their arses. Oil will be fuel contaminated. And I am going to deactivate the AFM to not have future trouble with it.