5Series.net - Forums - Noisy engine

Hi, I have a E39 535i 1998 that been resting for four years. But now its in trafic again due to my other car broke down. Since august it have been running well but when the snow came in december I did park it. It had no issues then. After about a Month I started it and the idle was uneaven when the engine was cold and it made a noice comming from the engine. Anyone have an idea what could be wrong?
UPDATE!! Discoverd small aluminium pieces in the oilfilter.