I had a week off and now I'm back on for seven days of 12 hour shifts. Still continuing, but at a slow pace. I was going to pull the rest of the interior out next, but curiosity about the engine was still nagging me. I decided to pull the coils and spark plugs to see how they looked. In hind sight, I should have done that before I ever turned the key. (Would have done it on my PPI, but honestly at the $2000 price, there was no way I was not buying that car.)
I started with the #4 cylinder. It had misfired and was easy to reach.
When I got the screws out, the coil practically fell out and came with a surprise: The spark plug tube came right out with it. A quick look at the inside end of the tube showed that it had melted and deformed from the engine overheat.
What kind of temperature will cause that? What other components will be damaged at that temperature? Could some of the black material in the oil filter have come from the spark plug tubes? This took my optimism about the engine down a notch. If I was keeping it, I'd probably replace the coils, tubes, and spark plugs, run it again and see if it improved much. I am not keeping it. I decided that there was no point in me looking at the rest of the coils. It's best for me to cease and desist from engine work - no more trial engine runs - and focus on getting the rest of the car ready for Rick.
That's about it for now. Oh, and here's a pic of the diaphragm from the AOS:
