Got it now, the noise my engine makes is like a sewing machine noise, is this normal or a fault?

Depends, can you be more specific? What type of sewing machine?

It's not just "Tappety", is it? In which case I've been told a tappy engine is a happy engine.

quite a loud sewing machine, doesn't sound like tappets, like I used to have with the mk3 escort. at first I thought it was the manifold leaking, but now I think it comes from the engine or gearbox. it comes from the passenger side of the engine though

Must be a singer

Is it a thrumming, thumping noise, or a ticking, tapping or clunking noise? Can you hear the noise when the engine is running, does it speed up in time with the engine when revved, or can you only hear it when the car is moving, in time with the speed of the car - if so, can you hear it when moving along but with the clutch dipped and engine idling?

What sort of noise do you expect the engine to make when its not running

duh
Oops I meant when it's revved up of course. Unless this is a gearbox noise and you have switched the engine off whilst going downhill to conserve fuel of course.

it is a constant noise, non variable, always there (when the engine is on!) and always the same tone