As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED. ADJUSTING ALTITUDE FROM FL 360 TO FL 380 AS SOON AS POWER(A/T) INCREASED ENGINE HAD 2 COMPRESSOR STALLS ABOUT 15 SECS APART. N3VIB INCREASED TO 7.0 RUNNING AT REDUCED POWER LOWERED IT TO 3.9. REPLACED LEFT ENGINE.