Here-in lies a little tip to make your variator last many years...
Whenever you start the engine, blip the throttle above 1750 rpm immediately to allow some oil to pass through that solenoid and fill up the internals of the variator. Either that or drive away straight away.
My best guess is that some people start their engines then go off and de-ice their screen, feed the cat, telephone the mistress, etc, etc, and leave the poor engine idling which f***s the variator because there's no oil running over that pathetic little white plastic washer inside the variator (and the metal splines too, item 4 in picture).
The classic variator diesel noise is probably the splines chattering against one another with wear from oil starvation.