I have a 03 4.6 V8 gt and it has a tic/knocking sound in the engine. I've done 2 oil changes w. Marvel Mystery oil included & a motorflush on to last one and still does noise. Lifter maybe? LMK PLEASE

there is kind of a difference between a tick and a knock. lifters tick,pistons knock. tick-tick-tick steady I'd think lifter. A nice long handled screw driver held against your ear and the other end touched to different places can pretty much pin point the area where noise is coming from

try putting Lucas in it if it stops or quiets down its a lifted

I agree with checking the location of the sound. Crummy aftermarket oil filters will starve the engine of oil for the first 1 - 3 seconds, a flat cam lobe or bad or collapsed Hydraulic Lash Adjuster, It's also common to have a Timing Chain Tensioner fail on this engine. I've seen several cracked or even broken out Flex Plates too. It all depends on where it's coming from and when.