Originally Posted by BillGrissom

Good info. I have never taken a turbo apart. I just thought it had ball bearings from things I have read. I recall some early turbos in the 1980's had problems with oil coking from heat-soak, causing bearing failure. Perhaps they meant journal bearings. Makes sense since the bearings are flushed w/ oil.

Something round, about the size of a ball bearing, was bouncing around in the #1 cyl of my 1985 engine, since there were circular depressions in the piston top, and similar on the pre-chamber outside. Don't know if that caused the failure at 330K miles. Several other cylinders had chunks missing from the pistons around the ring grooves, but not such pocked damage. It did make a bad noise about 6 months prior that, sounding like something bouncing around inside, then went away after a minute idling. When it made it the 2nd time, I drove ~2 miles before the engine stopped and wouldn't turn over.