The oil filter thing is true. Basically if the filter you are using does not have an anti drain back valve, all the oil will go back to the pan. On cold start ups, the oil now has to travel back to the top of engine, which would result in a ping. This would only last 15-30 seconds. Was the tick there before you changed the plugs? My truck ticks but its the fuel injectors. There kinda noisy on these trucks.
Some 5.4 had a piston slap, exhaust leak, and knocks on start up. Piston slap is first start up of the day and usually goes away after warmed up same with the knocks on start up. Exhaust leak look for busted studs, or if it's cold outside look around the manifold or exhaust system for smoke or Look for a area that is slightly blacker around the manifold that will be from a bad gasket leaking. Also look for cracks in the manifold. Also check your cats bolts and tighten them up. (i thought I had a manifold leak but it was my cats being kinda lose.) lol
My exhaust leak can be heard over my M/T's. But its in a spot thats not threatening to block/manifolds. Its on my EGr tube comingoff the manifolds.
prolly most likely your piston return spring is broken http://kalecoauto.com/index.php?main_page=product_info&cPath=3&products_id=27 Sent from my DROID X2 using Tapatalk
