Hi all.. I have a 2001 1.8Ltr Duratec He engine... the problem is it has a knock to it... the only way i can describe it is. That it sounds like a drill... like if you put a plastic ruler on the end and turned it on. so it flaps round against a table... and when you rev it.. its get faster... It sounds to me that sounthing has snapped... Performance is no different just makes this noise... so bit confused. Does not smoke or anything... just makes this sounds... and its a loud noise... Not just a light tap...