Any stains on the ground?  I would say if not then your burning up antifreeze.   Your oil pump could be on the way out, or it could be one of the other 20 issues.  I would say norrow down the issue, find someone to help you take a look at it, or run Castrol 20w 50 with a can of B2 until it dies and replace it.  but I would go with option one or two before giving up and killing a probably ok engine.