First post here guys. Back story, going through my dad's '65 230sl trying to get it running again. Went through and did all the filters/fluids I could find. Car needs some work and hasn't run for probably 20 years. Everything has been easy peasy until I tried to turn it over....
Pulled plugs, blasted out a lot of chunky/crusty white debris out of cylinder 6. (I think that's 6, closest one to the firewall). Put some oil on top of the cylinders to try and turn it over a little to get some new oil pushing through. Starter goes clunk, engine is frozen up tight. Bought an boroscope and here is what cylinder 6 looks like after blowing out all the bulk chunks. The other 5 cylinders are looking pretty good, but I'm thinking the head gasket went on it and leaked coolant into the rear-most cylinder. I've tried to manually turn the motor over from the crank bolt and also tried with one rear tire off the ground. No dice, it's locked up tight. I actually loosened the crank bolt trying to wiggle the crank both directions if that gives you any idea of how locked it is. I have a ton of PB blaster soaking the top of the pistons at the moment but I'm assuming at this point it needs to have the head pulled, head gasket replaced, and have a good look at that rear cylinder. I can probably take the head to a machine shop to hot tank and clean it up.
What would you do? The ugly pics are the rear most cylinder, I put in a few others of the other cylinders that look much better.