2007 VW Passat TDI sport smoking and smelling burnt

[Reefer madness]

Hi I'm new to the forum so if this topic has been extensively covered I'm sorry. 

I've just bought a 2007 VW Passat TDI sport estate. When you start it up from cold it's a bit lumpy at idle, but the when it's been left to warm up it's smells quiet bad, like a really old burnt out engine. It'll tickover nicely when warm but there seems to be a lot of black / grey smoke coming out the exhaust. Are these signs of a blocked up EGR valve or something else. Please help, I've only just bought the car and I just hope it's not a lemon cheers Gary 😂

[Volkswagen Owners Club]

I would say that it needs a good blast to clear it through especially if it was only driven locally.