I drove it for 10 miles to day, and after that the sound was gone, I pushed it quick up to around 4000 rpm. and the sound was gone.
So I guess that must be fine

But after a rebuilt you are a bit scared that something went wrong under assembly but engine runs veru smoth now and has a realy exelent idling.

Now I just have to adjust the whole ASR / Electronik Actuator as the idle is a bit high.
But that should be an easy job

thanx for the help and tips.