So I have an '82 240d with about 370k miles on the odometer. I've begun to notice that the engine doesn't quite shut off with the same authority. There's maybe a one second delay after switching off the ignition, then it will shut down with a quick shake. Should i be concerned that this is a warning sign of impending vacuum pump failure? Is it something that I need to address at this point or should i wait and see if it gets worse? Unfortunately my long time mechanic has retired and I'm hesitant to take it into a shop that I'm not familiar with (and that i can trust has the competence to work on these old diesels).

Are there some other, more benign issues that I should keep in mind for when i do eventually find a shop? From what I understand, there are no rebuild kits for the vacuum pumps. Any feedback is appreciated!