What was found
(CAN) DURING TAXIING, IN PREPARATION OF A REPOSITIONING FLIGHT, THE PILOT HEARD A LOUD NOISE REPORTED AS A COMPRESSOR SURGE. ENGINE POWER WAS PULLED BACK TO IDLE AND THEN SHUTDOWN. AIRCRAFT RETURNED TO THE HANGAR. THIS WAS THE SECOND EVENT. THE PREVIOUS TAXI RUN, THEY HAD A LOW OIL PRESSURE, SHUTDOWN THE ENGINE AND RETURNED TO THE HANGAR FOR INVESTIGATION. THEY FOUND LOW OIL LEVEL AND ADDED 2.5 QUARTS OF OIL,TROUBLESHOOTING IS ON-GOING.