Mep 003a runs perfect BUT now has a rotating noise during run time

Mep 3 kW. 3 phase.
During run time developed a rotating very disturbing noise .
All functions run well full voltage ok
Also during shutdown after engine stops rotating this odd and added noise continues for a few seconds more until stop
What the heck is this Bearings? Brushes ?
It’s like metal on metal Scraping
I checked the oil in full. No metal flakes at all very clean
Is this engine noise or generator noise
Some one must have had this symptom before ????