comp 822 lifters

All depends on the lifter to bore clearance, lifter preload, the oil used, and the spring pressures. With the exception of the oil type any of those individually or in combination can make the lifters bleed down. If you used the 822s (stock type lifters) where Comp recommends the 867-16s and adjustable valve train, and/or you have some loose lifter bores (very common), and/or the preload is on the higher side they may bleed down because of the spring pressure. The 822s in my truck are quiet even when left sitting for weeks without running.