What was found
ON TAKEOFF, FWD ANNUNCIATOR OVERHEAT LIGHT & NR 2 ENGINE OVERHEAT LIGHT BEGAN FLICKERING ON & OFF. 1ST OFFICER IDENTIFIED ENGINE & CALLED ALL ENGINE NORMAL. REQUESTED A RETURN TO FIELD FROM TOWER & ON LEVEL OFF BRINGING POWER LEVERS BACK OVERHEAT LIGHTS EXTINGUISHED. RAN QRH & RETURNED FOR NORMAL LANDING. MX FOUND 13TH STAGE SENSE LINE TO PRESSURE RATIO BLEED CONTROLLER LEAKING AIR AT FITTING. MX RESEATED & TIGHTENED THE SENSE LINE & PERFORMED A LEAK CHECK. ACFT RETURNED TO SERVICE. DEFERRED NR 2 ENGINE OVERHEAT DETECTION PER MEL 26-2-1 DUE TO NR 2 ENGINE OVERHEAT TEST INOP. ACFT RETURNED TO SERVICE. R & R UPPER LOOP ELEMENT ON NR 2 ENGINE. PERFORMED OPS CHK & CLEARED MEL 26-2-1. ACFT RETURNED TO SERVICE.