99 1.8 Possible smell of engine oil ? - jp147
When I lift the bonnet up on my car (which is a petrol) after I have used it, I think that I can smell engine oil in the hot air that rises from the top of the engine etc. Do you think that most cars have this sort of smell under the bonnet when they are hot and how would I tell if the rocker cover was leaking ?
99 1.8 Possible smell of engine oil ? - Screwloose

1.8 Focii are pretty famous for splitting the breather hoses from the PCV valve on to the back of the inlet manifold. Might be a good place to start looking for an oily smell.