Update:
Well the plot thickens on my timing chain tensioner issue....really weird situation. Just swung by the shop and talked to them, some high strangeness indeed!
Firstly - the engine is eat-off clean inside.
So the root cause? The bolts that were holding the timing chain tensioner to the block both snapped causing the tensioner to become cattywampas and the spring broke (piece of it was in the oil pan). The timing chain was not stretched/was within the specs. Can't believe I drove it for ~6 mos. this way including several days of hard mountain hooning in GA and over 40 runs down the drag strip. The loud noise on startup in April when I first thought something was wrong had to be those bolts breaking. The aluminum in my oil fiter last time was clearly from the timing chain cover b/c you see where it rubbed. The strangeness part now...1) the bolts that broke were not factory parts, they were v. lightweight aluminum/not the correct fasteners and 2) there are paint marks all over for timing it...that is not how they come from the factory according to them (
Alfie Mendoza - comments?). Our guess is that since I bought this car new with about 50 miles on it (it was in the showroom when I got it and likely was driven at some point by dealer folks) that either at the factory or port something was wrong and it was re-timed and the bolts...who knows why they used those non-factory fasteners. She called the dealer I bought it from and they had no records of any repairs like this that I wasn't privy to when I bought it - that doesn't necessarily mean they didn't do this. I'm incredibly lucky to not have to have a new engine. My shop is great. Should have back on Wednesday.