I was directed over here by the BMW R1100S guys over on the Pelican board.
My neighbor gave me a '95 M3 that had been sitting for the last two years. It's a fairly clean car for having 201,000 miles.
With a new battery and oil change it started up quickly. That's the good news.
The bad news is once warmed up there is considerable valve lifter noise. My diesel pickup is quieter. There is also a misfire when warm but I did find a cracked insulator on one of the spark plugs. The valve cover gasket was also leaking into the spark plug holes. OK, easy fix. Revving the engine did not clear up the lifter noise.
Another anomaly is the oil pressure light takes 2-3 seconds to extinguish on a cold start. So now I am suspecting oil pressure/air in the oil problems. Yesterday I pull the oil pan. No cracks in the pickup tube or damaged to the gasket.
What I did find were small bits of black plastic on the pickup screen. As large as a couple grains of rice. Timing chain guides? I don't of any other sources of plastic inside the engine. Are there places in the oil galleries for this plastic to lodge and cause oil starvation to the top end causing my lifter rattle? Any other sources for plastic chunks?
Unfortuntely I am under a time crunch otherwise I just pull the engine and go through it. Although, on another webpage, they say the life expectancy of the S50 is only 200k miles. I don't have time for a LS swap.