Good afternoon are 4.4 tdv8 engines prone to locking up? my tdv8 yesterday made a bit of a rattling noise, a bit of smoke,, managed to get it on my drive thought i might try and start it today it cranked normally but did not start but then made a loud clonk and stopped cranking, I pulled the starter out and tried to move the engine by moving the flywheel but it was absolutely solid, my best guess is that its swallowed a lump of turbo and its jammed in a combustion chamber, valve, piston or am I looking at something worse ! any thoughts ? I was under the impression the 4.4 tdv8 were more durable than the tdv6 and the 3.8 tdv8

More likely to have spun a main bearing shell and the resultant lack of oil pressure caused a big-end bearing to seize.

The TDV8 in both the 3.6 and 4.4 use exactly the same main and big-end bearings as the TDV6/SDV6 excepting that there are more of them and that the thrust bearings attached to the rear main bearings are different. However the V8 crankshaft doesn't flex the way that the V6 does and doesn't break when a big-end seizes.