Earlier this year my '80 240D ran away. My son unknowingly overfilled the crankcase with 3-4 quarts more oil than it should have had. The car had smoke prodigously before, but when he cranked it up, it kept going higher and higher. He turned off the key but it kept going. Opened up the hood and couldn't see the shutoff lever through all the smoke. The people in the paint shop he was parked in front of came running out with fire extinguishers and the people across the street called the fire department.
My son commented that he didn't know the engine could rev that high.
I came by 15-30 minutes later and noticed the breather hose was disconnected. Son acknowledged that it came off shortly before the engine stopped and that oil was spraying out of it. That answered the question as to why it ran away and why it stopped.
Engine would only start with ether after that on two cylinders. 3 cylinders after it warmed up. And a big rod knock to boot.
Gave the car to charity. It was sold to someone who is going to rebuild it.
