First time poster, long time browser! This board helped me through my first head gasket replacement a few years back but I'm running up against a few obstacles this time around that I need some help with.

I have a 2000 Disco II torn down to the block. Sent the heads off to get them resurfaced and to have a valve job done. Just got them back from the machine shop today and while I was cleaning the block and cylinder heads, one of the pistons heads pushed all the way into the cylinder. None of the other pistons moved. Do I have a broken piston? What are my next steps to further investigate?

Thanks!!!

 

Pictures might help. Do you mean one of the pistons touches the cylinder head? The pistons will be at different places, so if that's what you mean it's normal.

 

When you say "pushed all the way into the cylinder" do you mean it went down into the block?

 

pull the sump and check from underneath....

 

Take a 24mm socket and attach it to a wrench, attach it to the crank pulley and rotate the crank while looking at the pistons.

 

Yes, exactly. I'm going to to try DustyLBottoms suggestion and try to rotate the crank.

 

Ok, while doing this all of the pistons move freely except this one. It did push to the top of the block but wasn't pulled back in like the other pistons. Upon pushing it in manually, it would push back out after a few turns on the crank shaft. Could the push rod have detached from the piston head?

http://redmeatdesign.com/disco/IMG_3286.JPG
http://redmeatdesign.com/disco/IMG_3287.JPG

 

Sounds bad. Perhaps the connecting rod big end cap or bolts broke? Or as you say maybe the piston head disconnected, though I think that would be more severe of an issue. Either way, you'll probably want to pull the oil pan off to be sure... and you'll probably need a rebuild.

 

Not a "push rod", it's a connecting Rod. But yes, something's broken. Now it's time to pull the oil pan and see what's going on.

 

Thanks for the reply, I'll pull the oil pan and see what I find.