sounds to me glow plug is lose, or your missing the shim between the block and the head. you could make sure the head is tight on the block. And last make sure the holes the screws go in that hold the head to the block are not stripped.
Sometimes, that is what you have to do. It sucks, but it's just one of those things with nitro. Been there many times myself. Hit us up if you need any further help. We are always happy to help out.