Camshaft lifter failure

[Grumpy Bear]

2 hours ago, Ladypumper said:

My 2018 Chevy Silverado had service engine light on and horrible rough idle at 130,000.  Have always driven Chevy.  Put over 300,000 on a lot of them.  Turns out this motor has variable valve timing.  When you get to rd speed it drops off some of the cylinders.   They do that by dropping oil pressure which causes excessive cam wear.  Supposed to improve mileage which doesn't work.  Make a kit to override but installing the kit nullifies any warranty.  Chevy needs to step up!

If I'm reading this right you are saying cylinder deactivation is controlled by "dropping oil pressure". And as you have concluded cam/lifter failure is the result of low oil pressure? Low pump pressure? Take note of a point at 1:36 on. More note a 2.20 on.