hi, have an '02 doblo 1.9 diesel(i know), coming home i suddenly had a severe lack of power, and the noise from the engine(which has been there for two weeks) got very loud. oil and water okay, but sounds like only running on 3 cylinders, poss i think camshaft is f*****, any ideas where i can get a new cyl head if i need to, and is this a common fault??? am not going anywhere near a dealer if i can help it!!!