As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RTFL DUE TO NR 1 ENGINE HIGH OIL TEMPERATURE INDICATIONS. BOROSCOPE SHOWS A CRACK IN THE CRACK OF INNER LINER NR 4 PANEL. AIR/OIL HEAT EXCHANGER ALSO BELIEVED TO BE FAULTY. REMOVED ENGINE AND REPLACED WITH A NEW ENGINE. ENG 726661 SENT TO SHOP FOR OVERHAUL.