What was found
(CAN) DURING CLIMB, THE CREW OBSERVED ERRATIC OIL PRESSURE INDICATIONS AND ELECTED TO RETURN TO POINT OF DEPARTURE. THE ENGINE OIL PRESSURE CONTINUED TO REDUCE AND THE CREW PERFORMED AN INFLIGHT SHUTDOWN. INVESTIGATION REVEALED A FAULTY MAIN OIL PRESSURE FILTER WITH A REPORTED COLLAPSED INTERNAL ELEMENT. MFG WILL CONTINUE INVESTIGATING THE EVENT AND ADVISE OF ROOT CAUSE ONCE ESTABLISHED (TC NR 20071128014)