I've got a great old 250D (1995), about a month ago I turned off the ignition, took the key's out and was about to exit the motor when I realised it was still running... I had to stall it to kill the engine. No one, so far, has been able to give me a reason why this is (still) happening, or how to remedy my problem. Apart from the obvious: taking it to a Main Dealer and paying a small fortune. Any help/advice would be really appreciated.
Thank you.

 

Mine was the door lock vacuum box leaking.

 

Thanks, I'll try searching for what you've suggested and see if I can fix the problem. Your help was much appreciated, thank you both.