help needed passat estate

[jaypassatestate]

hi all just wondering if there was a decent garage in middlesex that could diagnose if my tappets are knackerd....its just when accelerating down narrow roads with cars down it either side i can really hear the tappets,i was told it could be an exhaust manifold but it sounds far to noisy also its using a quarter of a litre of oil every 4 weeks the passat is an petrol 2.0 azm engine with autobox 4 speed just had service done with cam belt and water pump mechanic said exhaust manifold was fine... any one with any known issues and a good garage would be gratefull jay.....ps..its only done 54000 miles....2001 car