Hi im new here. My 1.9 tdi has a problem. Every time you fire it up it rattles the tappets until the oil pressure builds up and it goes quiet. In its life its had issues with tappet failure and it has just worn through a black hardened set and damaged the camshaft. I thought it could be the valves in the oil filter housing not holding the oil in so fitted a new housing but no different. Anyone else think it could be the oil pump itsself causing the oil to drain back overnight? Plus if it is, are they easy to change?