What was found
AUDIBLE RUMBLE WHEN ADDING POWER AS A/C POSITIONED RUNWAY. CYCLED ENGINE BLEEDS AND RUMBLE STOPPED. ON CLIMBOUT RUMBLE RETURNED AT CLIMB POWER. RUMBLE DIDN''T RETURN DURING DESCENT APPROACH AND LANDING. NO FLIGHT CONTROL PROBLEMS. INSPECTED A/C VISUALLY, NO FAULTS NOTED. INSPECTED 01-02 ENG INTAKES AND EXHAUST. OPENED AND INSPECTED BOTH ACM COMPARTMENTS, INSPECTED WATER SEPARATORS. REMOVED AND REPLACED L/R 35 DEGREE VALVES AND RT CONTROLLER. PERFORMED ENG RUN AND BLEED SYS CK OUT PER PFHB. ALL CKS NORMAL.