I've noticed a quiet noise continues for approx 30 seconds after I switch the engine off on the C30, seemingly stopping with what can only be described as a quick gurgle. Attempted to video it this afternoon although not sure on sound quality!
https://vimeo.com/user121451657/revi...507/a1b159f87c
Not yet so familiar with diesel engines - sounds like it could be injectors?
Video shows area on front right side of engine, by the air intake/filter housing.