2012 Sierra 5.3L not sure about block, uses about 1 qt by 3k after oil change, sometimes more. Started consumption test at dealership first 2k no change so I dropped it. Had #7 plug go bad, didn't think to ask the mech about the plug, I didn't think it was connected now it makes me wonder.I use pensoil platnum pure synthetic 5w-30. Oh yea about 55k miles. If there is something I should do or can do to eliminate this problem please let me know. THanks