Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
I am sorry for the long wait
this is a 5.3 engine without the active fuel management system to shut of cylinders for better fuel mileage ?
is this an upper ticking like a lifter type noise ?
where you able to listen close with a stethoscope or something similar ?
the odds are this issue is a lifter that is loosing its prime and seems to be collapsing on and off
the best action to take is to remove the valve cover and make sure there are no broken valve springs
if the valve springs check out good the next step is the lifters need to come out and the cam lobes need to be checked for any wear if the cam lobes look good then replace the lifters
at this point that is the only thing to correct this issue