Some 535is had turbo issues. Can someone clear up 1) what the issue was 2) what the fix was 3) what production dates encountered the problem 4) when, if ever, the issue was solved by the factory with no more cars shipped with turbo problems?
The issue with the turbos was the waste gates not sealing properly or the actuators actually failing. The parts were improved. Any N54 engine could have this issue and the fix was to replace the turbos. But always first need to check the system for vacuum leaks and the pressure solenoids for failures. This isn't so common that every car is needing it but yes it does happen mostly to higher mileage vehicle. The tell tail sign normally is rattles and check engine lights.