Hello all I'm a newbie with a question about my 85 Chevy 1 ton 4x4 with a 6.2 diesel. The truck has been sitting for 10 years and I'm looking to get it running. The problem is I tried to turn the engine with a breaker bar and it will turn about half of a full rotation clockwise and the same counter clockwise but then stops solid with a clunk sound. Any advice is greatly appreciated.