Travelling home, my engine suddenly turned from a very quiet diesel to a
rattly one.
I called out AA and mechanic said it was probably an electrical fault in
engine management and motor had reverted back to a std diesel with knocking
and rattling from the left hand side when looking in the bonnet.
Took it to main dealer and the mechanic could find nothing wrong ??
But I know it is a lot louder now than it used to  be.
Any ideas please.   ( 12months old & 12K miles)