I happened to find the article below while searching for the elusive source of a possible vacuum leak in my 81 380sl. According to the article, vacuum leaks can be caused by a valve cover gasket, oil cap gasket, and even the rubber grommet on the dipstick.
Has anyone ever heard of or experienced these things affecting the idle on a 116 or 117?
Pelican Technical Article: Mercedes Benz - Fixing Common Vacuum Leaks
Thanks in advance for your usually enlightening replies