As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MSO FLIGHT NR 383 - DURING CRUISE, MASTER WARNING NR 1 OIL PRESSURE GAUGE SHOWED NO PRESSURE AND OIL TEMPERATURE WAS INCREASING. SHUT-DOWN ENGINE AS PER E/A CHECKLIST. ADVISED F/A'S TO PREPARE CABIN FOR NORMAL LANDING AT MSO. AIRCRAFT STILL OUT OF SERVICE. MAINTENANCE CHANGED ENGINE.