What was found
FLIGHT 3115 FROM ROC TO DCA - WHEN TAKEOFF POWER WAS ADDED THE FLIGHT DECK AND CABIN INSTANTLY FILLED UP WITH SMOKE. THE TAKEOFF WAS ABORTED AND THE PLANE WAS EVACUATED ON THE TAXIWAY. MAINTENANCE PERFORMED ENGINE RUNS AND DETERMINED THE SMOKE TO COMING FROM THE LT ENGINE WITH THE PACKS SELECTED AT A HIGH POWER SETTING. THE AIRCRAFT WAS FERRIED WITH THE LT PACK OFF TO IND FOR A POSSIBLE ENGINE CHANGE. MAINTENACNE BOROSCOPED THE ENGINE AND FOUND THE LT ENGINE 0 CARBON SEAL LEAKING. REMOVED AND REPLACED 0 CARBON SEAL. ENGINE RUNS WERE PERFORMED AND THE ENGINE OPS CNA LEAK CHECKED GOOD.