As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ETOPS SIGNIFICANT SYS - TOP OF CLIMB TO FL380 (THE UPPER EICAS SCREEN) EGT INDICATION LT ENGINE SKEWED A COUPLE TIMES FROM NORMAL 729C TO 445/542C: DURATION OF SKEW WAS 3 TO 5 MINUTES EACH EVENT. FOUND TGT THERMOCOUPLE AT 8:30 O'CLOCK POS LOWER LEAD & NUT COVERED WITH OLD OIL LEAK RESIDUE. REMOVED & CLEANED LEAD & NUT IAW MM 77-21-00-206. CHECKED BOTH CONNECTORS AT JUNCTION BOX FOR CLEAN & SECURE PINS. REINSTALLED CONNECTORS. RAN ENGINE EGT INDICATION NORMAL.