As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER CLIMB-OUT, AIRCRAFT EXPERIENCED A STUB WING OVERTEMP WITH SUBSEQUENT PACK TRIP ON THE LT SIDE. PILOT RETURNED TO BASE. INSPECTION REVEALED HEAT EXCHANGER 'BLOW-OUT' RELIEF VALVE LEAKING BLEED AIR INTO STUB WING. VALVE WAS REPLACED WITH NO FURTHER PROBLEMS.