What was found
(CAN) ON DEPARTURE, A FUME ODOR WAS DETECTED IN THE FLIGHT DECK. CREW WAITED A COUPLE OF MINUTES FOR THE FUME TO DISSIPATE IAW A BULLETIN. WHEN FUMES DID NOT DISSIPATE THE CREW DECLARED A PAN PAN AND RETURNED TO DEPARTURE, WHERE AN UNEVENTFUL OVERWEIGHT LANDING WAS CARRIED OUT. MAINTENANCE IS CURRENTLY INSPECTING THE ACFT. TROUBLESHOOTING C/O IAW EMB 21-20-00-810-803-A. HIGH POWER ENGINE RUNS COMPLETED FOR 1 HR WITH ALL BLEED COMBINATIONS NO FAULTS SERVICEABLE.