A Wizz Air Airbus A320-200, registration HA-LWT performing flight W6-3303 from Cluj (Romania) to London Luton,EN (UK), was climbing through about 4000 feet AGL out of Cluj's runway 25 when three loud bangs within a second were heard and the crew received an ECAM message indicating "Eng. No.1 Stall", the #1 engine's (V2527) EGT also went over limits. The crew reduced . . .