I think it may well be that a chain has skipped or broken teeth off a cam... it may well be related to the startup chain noise... my car used to do that on a regular basis, then the noise went away for awhile, then recently I noticed the startup chain rattle happening again.
This is not fun, but I am looking forward to the learning experience... I'm also looking forward to the opportunity to finally fix my ATX leak while dealing with this problem... gotta see how the $$ situation turns out... time to kiss a$$ to my employer and my bank
