Another No Compression/Uneven Cranking

[blown99]

Had another 365 come in on the hook with a no start with uneven cranking. No codes, all is good with the hard start no start diag. Pull the glow plugs and do a compression test. All had 40-60 psi with the exception of one that had 100 psi. Did a leak down test and found the air going into the crankcase. Bus only has 17K on it. I squirted oil into the cylinder, disconnected the glow plugs and gave it a little starting fluid. Cranked the engine a bit and it started. Gave it a good drive and parked it, started right up the following morning. This is a school bus, as was the last one I ran into with this problem. This one was definatly sitting for a while. The turbo vanes were frozen solid with visible rust. The unison ring was stuck to the housing and had to be pryed off. Strange how the rings are sticking after sitting for a month.