Refer to the following applicable SIBs before replacing the valve seals. ? B11 07 11 - Turbocharger Failure: Oil Supply and Return Line Blockage and Proper Repairs ? B11 07 12 - N63 Engine: Oil Consumption and/or Rough Running Complaints ? B11 01 13 - N63 Engine: Engine Oil Consumption, Engine Oil Top-ups and Refill Capacity ? B11 03 13 - Engine Oil Consumption (all models) If the valve seals are leaking, one of the following will help determine if the seals should be replaced. ? Smoke from the tailpipe when starting or aggressively accelerating and decelerating the engine ? Excessive engine oil consumption ? Spark plugs fouled with engine oil.
