One more thing , now I remember , I believe a VQ35HR motor in there ? That's the one with w/pump INSIDE FRONT timing cover, driven by timing chain .Mechanic drop something in there , force chain onto pump causing distortion , bad re-assembly - ANY of that can tear up a motor = "chainsaw effect".
You hear doing a timing set and w/pump at same time ? This motor looks like it allows you R&R the
pump through a small cover plate - very cramped working chain + mounting pump , and if they ever thought to offer the typical chain , guide , tensioner ,plus w/pump - cost = $$$$$$$$ 4800 + ? Ya know.
p.s. a "Magnetic Drain-plug" is a good visual indicator of metallic contaminant/ wear buildup in an engine . It's job not to be confused with PRIMARILY CLEANNG a motor , although you obviously get a little of that benefit too
Small amount of extremely fine "metallic mud" = normal , but start getting big as grains of sand/chunks = ACCELERATED DESTRUCTION