It should be fine to drive on a knackered dephaser, it's just the metal plates inside that seperate the two different oil galleries to advance/r****d the timing have worn and start making that rattling noise. They have a tendancy to go right after a belt change!As you say its ok to drive. Im going to be doing about 6 hours this week. Reckon its worth doing it and waitint till i get paid to sort it or shall i be worried and keep it off the road.