What was found
(CAN) PILOT HAD UN-COMMANDED SHUTDOWN OF APU ON THE GROUND. APU WOULD NOT RESTART AFTER. MAINTENANCE DIAGNOSTIC COMPUTER SHOWED HIGH APU OIL TEMPERATURE. INSPECTED APU OIL TEMPERATURE SENDER FOUND OK. FOUND OIL FILTER BYPASS INDICATION PIN EXTENDED. REMOVED CHIP DETECTOR AND FOUND SOME "FUZZ". REMOVED OIL FILTER, FOUND METAL SUSPENDED IN OIL. APU MFG INSTRUCTED SOAP SAMPLE. MFG INDICATED APU TO BE REMOVED FOR REPAIR BASED ON SOAP RESULTS.