Great info!
I think I found a suitable replacement low mileage 5.3. I'm hoping to go pick it up next week.
It came out of an 86 that had an electrical meltdown. The engine is good, but the injection system is gone. I'm pretty sure the parts from my 83 will fit but please correct me if I'm wrong!

 

If you can not hear it running be wary or make sure you get a warranty. These engines are pretty bullet proof the only that kills them is overheating and most commonly this causes dropped valve seats. The symptom is ticking that gets louder with revs. I haven't heard it myself but I have been told is quite audible.

The ignition system should be the Lucas constant energy this was fitted to the XJS between 82 and 89.

Before you you go buying another engine why don't you pull it down to see what the problem is if it is just rings foe example it might be more cost effective to just buy the parts, just a thought...

cheers

 

I was going to pull it out and pull it apart, but this guy is selling the motor cheap. If nothing else I'll get it for parts.
I'll post more once I get it home and can check it out better.

 

If its that cheap I would say go for it you can always keep the leftovers for parts

 

My thoughts exactly!

 

good call on putting oil in the cylinders. ive had a couple of older engines, especially engines with water in the oil that have frozen up from dry cylinder walls. oil or diesel works pretty well.