An A320 Captain reported fluctuating engine parameters during climb attributed by maintenance to a bleed malfunction; which had occurred on this aircraft previously. When the problem recurred; the crew attempted to turn off the left engine bleed valve. The result was bleed faults for both left and right systems. Crew descended to 10000 FT for the remainder of flight.

Narrative

Departed uneventfully; and due to first flight of day ensured engine operating for warm up in excess of 5 minutes prior to take-off. Approximately 5 - 10 minutes into climb through 16;500 aurally detected pack surging. Started to look at ECAM more closely and noticed approximate fluctuations as follows: left engine EGT +/- 10 degrees; N1 +/- 3%; as well as ANALOG (Needle) Oil Pressure +/- 5 psi; Digital Oil Pressure +/- 4 psi in correlation with surge. The Right engine was stable for climb condition. As left engine failure seemed possible; advised ATC of level off at FL180 to address 'mechanical' issue and slowed to 260 KTS; which resulted in significant power reduction. Surging subsided and left engine stabilized to closely match right engine. No ECAM messages at this time. Flying duties transferred to First Officer. Briefly consulted flight manual and immediately contacted Maintenance Control. Upon discussion and review of aircraft history; Maintenance Control suggested continuation and climb and then to turn off left engine bleed if problem returned. Climb to cruise at approximately FL340 was continued without incident and all aircraft systems working normally. Approximately 20 minutes at cruise altitude the bleed surging began again; related to left engine as previously described. Note: we were VMC for entire flight. As this problem progressed we noticed ECAM display of X-Bleed Selector fluctuating in movement from open-closed-open and changing from Green-Amber-Green. Coincidentally ECAM message 'Air Eng 1 Bleed Leak' occurred. Performed ECAM checklist and referred to flight manual but problem continued. A short time after ECAM message 'Air Eng Bleed Not Closed' displayed and selected Engine 1 Bleed 'OFF' and then 'ON' per flight manual with no effect; so reselected 'OFF.' In somewhat rapid succession; ECAM messages 'Air Eng 1 (2) Bleed Fault' and 'Air L (R) Wing Leak' occurred. Pressurization was monitored with no abnormalities at this time; and ATC was advised of expedited descent required due to possible malfunction. They provided descent to 10;000 feet and level off approximately 80 miles north of destination. Due to VMC weather and high workload environment; no further attempts to resolve problem were made by crew. Aircraft landed without further incident. Extensive log entry was made.