E39 M5 Engine noise
 

Hey fellas any help here greatly appreciated,parked my 2000 M5 a few night s
ago with considerable grinding and grumbling noise in front of engine,thought
by some chance it was steering pump related because of some apparent
groaning when cold (pump sounds).
Checked oil ,two quarts low,topped off ,checked steering reservoir about half
topped up then restarted and grumbling,grinding regardless of rpm...
sounds to be a little off or missing to say the least.
Am I looking at a timing chain related failure? Any help? thanks Bert
oh yes ,85k

It could be your Vanos units. It's not unusual to hear a rattling during startup and when cold but it should go away after a few seconds.

Engine noise
 

Have you purchased from NAPA, Auto Zone or similar outfit a $5 Stethoscope so you can pinpoint the grind? Let's start there so we can pull up the correct schematic when looking at possible causes. Look forward to your next post