It is a GM thing, others may have copied but I haven't deep dived it. Essentially a rod that is designed to collapse effectively shutting off a cylinder to produce better gas milage can fail and over time will wear the lobe off of the cam shaft.
How many of you are familiar with AFM(Active Fuel Management)....
I am in the process of shopping for a new vehicle and we will NOT have that feature on anything new moving forwrd.
So the 6.5 PRC and the 7 PRC have become staples for me as of late. Never thought I would have the .300 Win or .300 Weatherby not as what I reached for first in my closet but I suppose that happens.
I rarely clean mine. Once or twice a year for an average shooter should be enough IMO. If you are shooting thousands of rounds I am sure it's more important, but a few boxes a month won't require a cleaning.