XSeries-forum

Have 2005 3.0 diesel. Had low frequency whistle inside cabin and was diagnosed as turbo. Had new turbo fitted, decent one from GSF, and it is EXACTLY the same! Anyone any ideas?

I think you will find there will always be an amount of turbo whistle.
You will soon notice a turbo pipe leak, as the whistle will be much louder & the power will drop off significantly.

If some one conned you into buying a new turbo due to the whistle, then you need to go give them a bloody good kicking.

check the exhaust manifold mine sounded like a turbo whistle, turned out to be a cracked exhaust manifold (common on a 3.0d, try your rubber intercooler pipes for splits also i renewed the pipe seals (cheapest seals i found were from a bmw dealer)