A guide how to clean the carbon deposited on the anti shudder valve of modern volkswagen tdi diesel cars , usually people think its diesel throttle body but it is not true , its just an air control flap which works just 2 times , once on starting the engine and second on switching of the engine , as diesel engine are famous to vibrate or shudder at start ups and shuting down , this air flap adjust the amount of air pressure in the air track to reduce that shudder or vibration , to make the engine feel more refined,
But after some time this flap gets some deposition of egr gases mixed with oil vapour from crankcase ventilation system and form carbon depositions , which acts as a restriction in the path od smooth flowing air and harms performance and refinement .

problem - car shudders while turning off the ignition
video made on a volkswagen polo 1.5 TDI , same method applies to volkswagen vento and skoda rapid , skoda fabia jetta , audi a3 , audi a4

but the process remains same for every modern diesel engine , just location of component change .