Lost Compression today !

[dadysev]

So frustrating! I bought this 2001 3.0 with 280,000 km on it because i have so much faith in that motor! My old e46 had 500,000 km before i sold it and it was still purring.
Long story short i'm heading out on a 7 hour journey with the family and half hour in I feel the truck jerking so I figured ok it must be a coil, as I've changed the plugs recently. had a few spares so pulled over and found the non responsive one and swapped it out. No change, cylinder 3 is not being nice!
So I drive it home only to find when I do a compression test I'm getting about 5 pounds on that cylinder! Not happy!
I've seen a few vids talking about the rings getting stuck with carbon deposits from lack of oil changes, freezing cold days ( which it was -25 C), etc. I had all those symptoms!
When I recently changed the rocker cover gasket I was not happy with the sludge ad colour in the head. I also looked for any broken springs, bent or cracked valves, ( difficult to see) and there is zero noise. Engine still sounds the same.
Anyways I poured about 2 ounces of injector, intake, cleaner in the cylinder to soak until I'm back in a few days. I really hope this helps as I'm not in the mood for any valve work.
Any suggestions? I would really appreciate it.
Thanks and Seasons Greetings!