Is it a bend value 5.3 Chevy

Probably a broken lifter.

lifter is probly it but check rocler arm stud they sometimes pull out of head

yea and dont take it apart unless that piston is at tdc..could be guide , keeper ...

That isn't going to solve no oil pressure. Sounds like you have some serious issues with that motor

never said it would....first thing is to figure out the valve problem....

also after checking valve train, take the oil pressure switch out and crank engine..got pressure there?your engine will oil the botton end first..then thru the passage that the distributor completes when installed to the top end..your knock without hearing it could be top end or bottom end,,you said 1/2 space..between valve stem and rocker???? do you have anymore info??

What year is this Silverado? Does it have AFM (active fuel management / cylinder deactivation)? How many miles on it? At the top of the push rod stroke is it the same height as other pushrods when they are on the top of their stroke (valve closed)? Is the top of the affected valve spring the same height as the others when the valve is closed?

I've dug alittle more and the valve is fine. The pushrod doesn't go all the way up so I am assuming I have a collapsed lifter? It's a 2011 Chevy Silverado 5.3 liter with AFM. How hard is it to change out a lifter?

I am pretty sure the cylinder head has to come off. Also if the lifter roller came off (happens a lot) then the camshaft is likely bad. In some cases the bad lifter will damage the lifter bore and ruin the engine block. Sorry for the gloomy outlook, but it is what it is. Best of luck with it.

dont worry so fast...take the intake off to inspect the lifter/cam lobe.....

hey bob....want to know something? good,then ill tell you....on my chev motors i have sleeves in all the lifter guides... but the engine will have to come out to do that...1 or 8 off them...just board...

5.3 motors are known for lifter and camshaft problems. If you get a good one they will run for 200,000 miles or more, get a bad one and It will cost lots of dollars. If the roller comes off of the lifter it often chews up the cam lobe and circulates metal debris throughout the lubrication system. When these engines start ticking it is best not to drive them until the cause of the tick is determined. Replacing a lifter means the head has to come off and that is about 7 hours of fun.

hello;; bad needle bearings cause roller lifters to go bad all else is the same hardness... ask chet herbert... or ask me...

or doug now......rip chet..

It's the afm solenoid