I recently purchased an 95 PSD 5spd extended cab with a non-running motor. It has 218,000 miles on it. The previous owner said he was driving home one night, and the engine started missing and dumping some smoke. This happened about 1/2 mile from his in-laws', so he coaxed it into their driveway and let it idle for about a minute, and the engine stopped with a clunk.
He tried turning it over, and the motor would not turn. Ultimately, he pulled the drivers side valve cover (which he had bent a pushrod in a few months previously) and found that the 2nd cylinder back had a loose valve stem.
I bought it in this condition, and finally over the weekend got the head off. There is a dropped valve that is now fused with the piston, and the piston is cracked down the middle. Additionally, the head is scarred where the valve chunks smashed into it.
Aside from this cylinder, the others look really good. I can still see the factory cross hatching and no scarring is visible on the other cylinders.
So, my questions center around what I do now.
It looks like the combustion chamber in the head was pressed in -- can this be replaced? There is some damage in the head that looks like it could be machined out with minimal loss of surface area. The dropped valve's seat appears damaged (looked like the valve struck the seat), but a valve job may be able to fix it.
I have not attempted to turn the motor, would it be ill-advised to rotate the motor enough to have the piston move down the cylinder to check the wall for damage/cracking? Should I just pull the piston out of the head and inspect following that? If the wall is damaged, can I re-bore just that cylinder? Are there replacement sleeves available?
Is this a type of engine damage that is rare? Is it caused by poor maintenance, or specific behavior of some kind by previous owners?
Thanks in advance for any thoughts or advice.
I have included some pictures of the carnage.