metal in filter
sometimes the metal flakes come from the gear teeth in gear box.
RB211 from the thrust bearing and engine would be changed quickly.
on new engines get build debris from screw threads and bits being rubbed off.
on one engine that had been built incorrectly and discs and things where rubbing so much that the metal flakes blocked up the oil pipes on return pipes and oil was forced out of engine and tank emptied, did not have to count the number of little flakes and chips as when the magnetic chip detector when removed to look at the collection of debris, a mass of filings fell to the ground to many to count.
If oil gets too hot lumps of carbon turn up in the filters.