this engine has no cover on it... should a 2004 tdci engine have a cover over it...???

the guys in ford said it could well be the flywheel... i find that hard to believe

the car is 04 with 48k on it (hardly excessive)
the rattle sounds plasticy and vibrating rather than metallic
there are no probs with clutch,shuddering vibrating etc
the starter motor seems 100%

was advised by someoneelse that it could be tensioners on the fan belt or something... anyone comeacross this??

cheers