You may have excessive blowby. Next step is a hands-on inspection at a shop. Pay close attention to the amount to fix the car compared to what it's worth.
Use this link to find a good shop near you.
https://repairpal.com/repair-shops
Alex
RepairPal Certified shops can diagnose and repair your 2002 BMW X5. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.