Diesel Engine Knocking and Smoking

[selfsoiler]

I have just a call from my wife saying there is a lot of smoke coming from the back of her range rover sport 2.7 diesel and the engine is making a knocking sound. I have told her to leave it where it is and get a taxi home but as it is sunday I cant get anyone out to it.

Does anyone have any idea what the problem could be?

[selfsoiler]

So it sounds like something that can be fixed then? If its a common issue then there must be people out there who have had this happen to them and had them fixed. Is there anyone on here?