Just thinking. Your mechanic suggested soaking the rings with oil. That works with engines that have stuck rings because they have sat too long. In your case, it sounds like there is no gasket between #2 and #3 which results in zero compression. Lets hope the rings aren't buggered, that would mean a new block.

These Volvo blocks are pretty robust and should show no wear in the cylinder sleeves.

My fingers are crossed,

Klaus
--
Common sense trumps a PhD