As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: ELECTRONIC ODOR NOTED IN FLIGHT DECK DURING TAKE OFF AND CLIMB; CREW TURNED OFF CABIN FAN AND SMELL DISSIPATED UNTIL DESCENT WHERE ODOR GOT STRONGER. MAINTENANCE DETERMINED THE APU WAS THE SOURCE OF THE ODOR DUE TO THE OIL COOLER LEAKING. REPLACED APU OIL COOLER AND ACCOMPLISHED A SATISFACTORY LEAK / OPERATIONAL CHECK PER AMM 49-91-44** (CLOSED)