start up rattle

Hi all , Was looking for some advice / guidance regarding the engine sound i hear on cold start every now and again not always on every cold start and only happens on cold start never warm starts on my w204 c200 cdi c class , 2012 , I hear this rattle sound it varies the exact sound , however...

I have a 2011 Mercedes B class 180. It has developed a loud metallic rattle on first acceleration after cold start which causes passers by to turn their heads. It often lasts only 10-20 seconds and never recurs when warm Local agents have failed to diagnose the fault. They changed the...