Hello and welcome to Just Answer! I would be more than happy to assist you today.
First you must remove the intake and exhaust piped from the turbo and inspect the impeller inside. Check for excessive play--- signs of the blades touching the housing and oil. When the bearing in the turbo fails it will cause your issue. Also check all hoses for the intake system/charge air system to ensure there are no loose clamps or damage. Allowing boost pressure to escape. This too can cause a nasty noise. let me know... Thanks