E63 startup noise after sitting..
Without further ado, I have a new issue to bring forth: when my E63 sits for maybe 30-40 minutes or so, there's a rattling noise that seems to come from the bottom end which lasts 1-2 seconds and dies down gradually toward the end of those 2 seconds. It's not so much a metal-on-metal grinding noise as much as it is a flapping noise. I'll try to get a recording tomorrow when I do an oil change. What I noticed is that with back to back starts, there's no noise, which lead me and other members of the local Benz club to think it's oil related.
It doesn't sound like a lifter tick nor a camshaft adjuster grind - if someone told me it was an undercarriage tray vibrating, I'd believe it because it sounds just like that.
The oil was changed 2000 miles ago, prior to my ownership, by a dealer which went with 5W-40. I'm going to change it out tomorrow for LiquiMoly 5W-40 High Tech, but given that the last oil change was so recent, I'm not incredibly optimistic.
Here's some potential context: Since my ownership, I've had the valve cover gaskets replaced to fix oil leaks. The current oil level is at the bottom indentation of the dipstick. Engine mounts were replaced 15K miles ago. I hear what I believe to be a chirping pulley, but haven't identified which one it is, as it hasn't gotten too bad just yet.
Any ideas? Anything helps, really - it's my last unsolved gremlin. Cheers!


