As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BLEED AIR DUCT PRESSURE INTERMITTENTLY SURGING BTWN 20-40 PSI AT ALTITUDES BELOW 8000 FT. OCCURRED TWICE ON CLIMB POWER SETTINGS (1.46 EPR). ON ARRIVAL IDLE POWER (1.02-.99EPR) WITH BOTH ISOLATION VALVES CLOSED AND RT PRESSURE WAS SLIGHTLY HIGHER SURGING. SEEMS OK (1.05-1.20 EPR RANGE). REPLACED PRSOV IAW MM, CHECKS OK.