What would cause one-half quart of oil to get sucked out of
the engine and be deposited on the rear hatch during a
freeway run ~= 250 miles at 60-65 mph?

Where did it get sucked from? There does not seem to be
any major oil leaks anywhere.

It has never happened before and my van seems to be running
ok.

Suggestions?

Thanks,

John-Reed Maffeo
Mesa, AZ