Have the same issue with my 2010 Sierra 5.3L using Mobil 1 5W-30. Anyone have any thoughts on switching to 10W-30? Could it 1) elevate the problem 2) cause damage to bearings or valvetrain. I think the 2010 introduced VVT to the 5.3 lineup so I'm a bit reluctant to do it but can not stand the lifter noise at startup.

 

Probably drop mpg a little and maybe quiet the lifters for a while but I doubt it will last. Is the truck new and in warranty? If it is, then get it fixed. Lifters aren't supposed to clatter when new.

 

lifter noise . i have a thread on a similar issue going on . but i also have a mis-fire associated with it . it was intermitten but became full time . i will reply to the thread i started when i have the vehicle back from the dealer (1-1/2 week now) it was a collasped afm lifter for sure.