My car has a tappety/rattle noise on tick over which sounds like its coming from the head , when you rev it it stops and comes back as it returns to tick over. It runs but its very lumpy, it doesnt want to boost either, i ran it up the street and the boost gauge wouldnt go over 0, then it cut out but started straightaway. The problem came after i drove it hard and it blew the oil cap off, the cap wasnt a snug fit. Anybody had this problem, can anyone help ? Ive read that people have had lifter problems, with the same symptons as what ive got.

The car has a new turbo on it.

I have got a spare bottom end just in case it is that.............