C12 Cat with bad camshaft and water in oil 70k miles on rebuild

I have 2002 Freightliner Columbia with a c12 catepillar with 70k miles on the overhaul I had done 2 years ago and I started hearing a ticking sound from my engine and got it checked and the #6 exhaust valve was loose so they tightened it up back to specs and told me If that sound comes back the camshaft is bad. Well the ticking came back 3 days later so I pulled it off the road until I could get another shop to look at it. I got it checked and found out I do have a bad camshaft by looking at it from the bottom end. But we also saw sludge like water and oil mixing coming from the exact same cylinder all of the other cylinders didn't show any signs of water and oil mixing at all. When I did the complete overhaul 70k miles ago I replace. Camshaft, head, cam followers that were bad(shop never informed me I should change all) I did a complete inframe also. Paid 13k now 2 years later I'm back with this problem and a water in oil issue. I really dont want to put anymore money into this truck I've owned it 3 years and this will be my 2nd time in the engine. I would sell it as is but it isn't worth anything like this so I will probably fix then drive it til I can sell it. Any ideas what's causing water to leaking in the same cylinder as my wipes lobe on my camshaft?

 

Update. I replaced the camshaft and all the rollers and sleeve oring and of course all the gaskets. Truck runs good. But after the 4th of work it sounds like the ticking sound is coming back mainly after the truck has warmed up pretty good. It seems like dejavu I am taking it back to the shop on Monday to get it checked out. It isnt as loud as it was of course but I can definitely hear something is off. The shop told me to bring the truck back in 1 month to get a overhead done on it. When they took the old cam out they told me they think the cam went out because the valves were adjusted too tight. My number 6 roller had a completely flat spot on it.