What was found
DURING CLIMB, PILOT REPORTED INTERMITTENT ADVISORY OF NR 1 ENGINE HIGH N1 VIBRATION, REACHED 7.2 UNITS, N2 VIBRATION REACHED 4.2 UNITS. AN OIL ODOR DETECTED. ACFT RETURNED DEPARTURE FOR MAINTENANCE. UNEVENTFUL LANDING. BORESCOPIC INSPECTIONS TO NR 1 ENGINE, FOUND EVIDENCE OF OIL CONTAMINATION OF HPC STAGES 3 & 4. R & R NR 1 ENGINE IAW EO A320RP71-005/05 R15. TESTED SATISFACTORY.