I have a tl from 05 with what sounds like a top end tick, I've listened and tried many things including changing out even the motion loss springs with new ones and swapping the the rockers and the shafts that they sit on, I'm starting to believe that it could be something different so I'm looking in the lower end of the engine for bad baring or piston slap but there's also never metal in the oil after being drained, someone please point me in the right direction, it doesn't lose power and it's only ticking well at idle, after changing the rockers and shafts the tick went away for about 30sec then came back sounding identical.