I just bought an 05 Sorento LX with a BAD engine. It does have 250k miles so thats pretty good testimony but the story goes like this,..the owner basically ignored a radiator leak and it overheated badly and died. He had a machine shop rebiuld the heads and a shadetree mechanic attempt to put it all back together. It was running horrible and there was a BAD oil/coolant mixing problem,..the oil looked like latte! The coolant was not real bad but had some latte colored oil floating on top. Anyway after paying $600 for it and towing it home, I did a compression test and all cylinders were 180-200 psi, all spark plugs looked good but found a busted ignition coil and the PCV valve hose missing, the large vacuum port at the lower intake manifold open to atmosphere and a fuel injector electrical connection busted. Also before I started the teardown I checked codes,..cylinders 3,4,5,6 had misfires and that was it! Considering I fix all the OBVIOUS issues with coils, injectors and vacuum lines and get the car running great,..what about the oil/coolant mixing? With good compression,..could it have a cracked BLOCK like the shadetree mechanic surrendered to? Could it be a leaky headgasket? OR HOW about a badly leaking oil cooler? Anyone ever heard of a badly leaking oil cooler? BTW I will check all timing marks tomorrow but I tend to believe they might be right with good compression on all cylinders!