Update. Fixed! It WAS the oil. I checked my records and while I had thought I only had 1k or so on the oil, I had a touch over 5k. I forgot about that 2500mile trip averaging 75mph last fall. I thought I changed oil right after that. Guess not. Oops. When I started it again to put it in position to change oil after sitting another week, it wasn't as noisy. Normal startup taps, but nothing worse. This was odd considering how it sounded when I last turned it off. Then I changed the oil and filter. Nothing on the magnetic drain plug. Good. Oil seemed dirty, but viscosity seemed fine. My "how long does it take to run off the drain pan and how much sticks to the pan" test seemed to show that the oil was in good shape. Guess not. These engines seem to be VERY sensitive about oil, which is not something that I have ever seen before.
This time I went with the German brand 5W40 Liqui Moly and a Napa Platinum (Wix I am told) 1042 filter. As soon as the oil pressure came up the engine got dead quiet. VERY weird. In fact, it was smoother than I have ever heard it at startup. Usually it needed a fair amount of heat in the engine to get that quiet. I don't know if that means anything, but I like the sound of it. We will see how it does in the next 5k.
So, don't be a paranoid idiot like me. Sometimes you just need an oil change. I guess seeing all the blown M96s that I have in shops in the last year or so has gotten to me...
Back to my hole.
