2011 Volkswagen Golf - dieseling after I turn it off?

I have a 2011 VW Golf TDI and it seems from my research that it is dieseling after i turn it off. it doesn’t always do this but sometimes it does, and there is also always a smell when it happens. today when it happened there was even smoke coming from my engine! is there something i can do to fix it? or do i need to take it to a mechanic? i just got my engine oil coolant and leak fixed so that shouldn’t be the problem. what should i do?

could be a dirty EGR. you should search the VW tdi forums