What was found
ODOR IN CABIN AT LOW ALTITUDES, BOTH TAKEOFF AND APPROACH (AROUND 10,000' AGL) STRONG ODOR AROUND ROW 20-22. RAN APU, ENGINE NR 1 AND ENGINE NR 2 AND COULD NOT DETECT AN ODOR. R & R RECIRCULATION FILTERS REF AMM 21-21-45, PB401. ACFT NEEDS OPS CHECK FLIGHT TO DETERMINE SOURCE OF ODOR. DISCREPANCY NR 2: OPS CHECK FLIGHT UNSATISFACTORY - NR 2 ENGINE BLEED ON, NR 1 ENGINE BLEED OFF - SMOKE SMELL IN CABIN SIMILAR TO OIL OR ENGINE EXHAUST. SMELL DIMINISHES WHEN BLEED NR 2 TURNED OFF AND BLEED NR 1 TURNED ON. SMELL INCREASES WITH INCREASE IN THRUST ON NR 2 ENGINE. R & R NR 2 ENGINE IAW MP71042-02, AMM 71-00-00-710-008, 71-00-00-710-025, 36-11-00-710-003-A.