My 2.0 TDI 6 speed has had various electrical issues which are part of the joy of modern cars however like most Diesels they are quite quiet when first bought but get noisier as they get older. I have a definite noise from low down on the offside of the engine which is getting worse. It is not a rattle as such just a diesely noise which is getting louder and very noticeable. Am I looking at a known fault which is going to go pop at some stage?

All the time or at a particular load/speed condition?

At idle. That is when it used to be quiet for a diesel but now it is getting louder.