voyager 1994 2.5td piston problems !?
 

I have a chrysler voyager 1994 2.5td with a loud noise... I am almost certain that it is the pistons. I have had a local mechanic out today to have a look and he has said that he thinks it is the pistons listening to the noise but he doesnt want to open her up to have a look as the chrysler engine is "fragile" (!?) he said that with a chrysler its easier and cheaper to replace the whole engine... has anyone else replaced the pistons? i think that the mechanics around here arent interested unless its a french make (we are in france) .... any advice would be gratefully received.
thanks
tintin