As per their small print -
All internal parts of the engine that are linked to the oil circulation system; gearboxes (with the exception of the couplings and coupling parts integrated into the gearbox); pistons; crankcases; crankshafts; crankshaft sprockets; engine blocks; valves; valve guides; cylinder heads; cylinder liners; camshafts; camshaft sprockets; connecting rods; turbochargers.
So that excludes fuel injectors, cats etc etc. Car must be less than 3 yrs old, less than 60k miles at fitment & claim limit of £4000 inc VAT, that isn't going to cover an engine claim imho.