ok so i just picked up a 84 380sl. its in good condition overall. now im completely clueless when it comes to these cars. the car does have a one or two issues. it does idle high only when its not in gear, im either thinking its a vacuum leak but what else should i look for? the thing that scares me is the mileage, it has 230k miles on it. how do these cars hold up with mileage that high? it is not a DD.