Two years ago, I bought my diesel Vanagon with a bad engine (the previous
owner had the oil pressure light come and she kept adding oil, but the light
wouldn't go out. She decided the light was broken and kept driving; needless
to say, the oil pump was bad).  I rebuilt the engine but the head seemed
fine, so I left it alone.  A year later it started to burn oil and a year
after that, I finally got around to rebuilding the head.  I should have done
the head at the same time.