the wife has a 1.4tdci fiesta and two injectors went and seals in the others £525 to fix!
not the same car but the injector problem is on the mondeo aswell, search the web theres loads of posts on it, it seems to happen around the 60/70k mark on 52/53/54 reg cars, they ‘apparently’ changed the head on later models.
if you find one take it for a spin, blast the heaters on and smell for fuel, if any whif comes into the cabin walk away. also listen to the engine and raspy/pinky noise walk away.
sorry for my crap technical terminology but we had a nightmare, but had to get it fixed as we had no choie and the car is now running fine.