Thought i had a decent starter, and the hotwire saved having to pull the damn thing in this weather.

Today i was in town, and when i started it, there was a funny noise that kept going til my next stop. Next time i tried to start it,only a grinding noise.

Apparently the solenoid didn't disengage and in just a mile wore its teeth off. Second time that has happened on this car ('81 240D). Previous time was with a Pep Boys starter.

Is this a common failure mode? Or is there some underlying problem that made it happen TWICE?