most duratecs have some sort of "valve" type noise, either the timing chain rolling over, noisy injectors, exhaust or belt tensioner, etc. If it's getting louder however, that is not good. Is it coming from the bottom end? You should be able to discern from a tap and a knock. Knock = bad. Do you change your own oil? Tear apart the filter, see if there's metal shavings inside. Or j ust get it back from the mechanic next time you get your oil changed. Keep us posted.
