I was having a quick convo with a friend of mine last night and he mentioned he has had some issues with his ST engine, basically its breathing excpetionally hard from what I could make out.

He mentioned there has been faults on these engine with a diaphragm spiltting behind the oil filter housing or something Can anyone clarify this ?

Have the ST's had any dramatic problems ? I'm guessing there is one or Ford mechanics on here who could answer that

Its not covered by warranty as its mildly modded so it needs to be sorted and he understandably doesn't want to take it anywhere thathaven't got a clue about the car.

Any help would be appreciated