330d turbo noise

I have an E46 330d, which has just starting making a significant hiss or possibly scraping noise when accelerating briskly. It appears almost
instantly you put your foot down and dissappears as soon as you back off. I am assuming that is it is a leak on the compressor side of the turbo, and it is booked in to BMW next Wednesday. Has anyone had a similar problem? I know that early 530d had overboost issues initially, but have any 330d had the same problem?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.