What was found
THE CREW REPORTED A BURNING SMELL IN THE AIRCRAFT WHEN INITIATING HIGH POWER SETTINGS. THE BURNING WOOD SMELL WOULD DISSIPATE AFTER APPROXIMATELY 30 SECONDS. MAINTENANCE FOUND THE NR 4 BEARING HOUSING ON THE LEFT ENGINE LEAKING WHICH WAS CAUSING THE BURNING SMELL AT HIGH POWER SETTINGS. THE NR 4 BEARING HOUSING WAS REPAIRED, THE LEFT OIL PUMP WAS REPLACED AND THE WATER SEPARATOR SOCK WAS CLEANED. NO BURNING SMELLS WERE NOTED WHEN THE ENVIRONMENTAL AND ENGINE SYSTEMS WERE CHECKED WHILE THE AIRCRAFT WAS RUN AT HIGH POWER SETTINGS. THE AIRCRAFT WAS RETURNED TO SERVICE.