Hi Pawl,
Appears the OP solved his problem on the previous post to yours,
Surely if the wastegate rod was thought to be a problem it would be easy enough to unscrew a few turns and see if the problems is resolved, common consensus IIRC seems to be that 13 threads visible is the norm, with the potential to reduce a few threads if the overboost does not cut in. Especially if a nanocom is not available.
Cheers