What was found
FLT 1047, JFK-BNA, AT APRX 21:40 PM RETURNED TO JFK, SMOKE/FUMES/HAZE IN CABIN & COCKPIT PASSING 8K FEET, GOT WORSE AS CLIMB CONTINUED. LANDED ASAP. FUMES SEEMED TO CLEAR A BIT DESCENDING THROUGH 2K FEET ON DESCENT. PERFORMED SMOKE/ABNORMAL SMELL IN PASSENGER, CABIN AND COCKPIT PER AMM 21-20-00-810-801A. NO FAULTS FOUND, NO SMELL PRESENT IN A/C. REPLACED NR 2 AIR CYCLE MACHINE & TURBINE BYPASS VALVE DUE TO COFFEE CONTAMINATION. OPS CHECK OK.