?N63T CRANKCASE VENTILATION LINES: LIMITED WARRANTY EXTENSION TO 10 YEARS/120,000 MILEAGE. For the eligible vehicles, BMW of North America, LLC (?BMW NA?) is extending the limited warranty for the engine Crankcase Ventilation Lines to: 10 years/120,000 miles as determined by the vehicle?s original in-service date Note: This bulletin is notice of a ?limited warranty extension.? This is NOT a notice of a Recall or Service Action. There is no immediate repair required unless the BMW vehicle is currently experiencing this problem. Customer Notification Letter Even though this is NOT a Recall, BMW NA sent VIN-specific customer notification letters in a phased release.