Here you can see my experience:

http://www.peachparts.com/shopforum/diesel-discussion/347663-my-om602-turbo-cooling-experience.html

Basically it over heated and now I am going through to see if I need to replace the head gasket.

Just ran a cooling system pressure test. Cooling system holds pressure to at least 30 psi. The cap opens too soon, but that isn't a huge deal.

Here is a youtube video of the bubbling system.

OM602 Cooling - YouTube

Is a compression test next?