If you've just fitted a new head, check your cam belt hasn't slipped and jumped teeth, that would explain the vibration as it would have been running out of timing, but unless the engine has thrown a rod through the side of the block, wouldn't explain why you can't turn it over? even with the timing out it would still turn but not fire.
Thanks guys , I was trying to ignore the word seized’ as I have Just fitted new head and belts and it was all going so well.have someone with Mitsubishi diagnostics coming round after Christmas and hoping its not.
Driving my 2004 L200 k74 today the engine suddenly died . It would not restart or even try To turn over and felt like a jammed starter. Battery is fully charged at 12.6v. I had noticed in the past few days that my gearstick was shaking through about 2” when idling or in neutral ,but when driving in gear it smoothed out and was hardly noticeable. I suspected the engine/gearbox mounts. Could these be related? Welcome any ideas car has done 79,000