I think it should also be pointed out that unless you drove the car with the needle pegged in the red for more than a couple of minutes, this car more than likely already had head gasket issues.
Before you run out and buy a new motor, I would have a professional, independent BMW mechanic take a look. If it is just a matter of replacing the headgasket, you'll be much better off paying to have just that done, instead of buying/shpping/installing a new motor.
I think it is much more likely given the description that you gave that this car already had a blown headgasket when it was sold to you. Blown headgaskets cause overheats, and if you really did shut it off quickly, the motor itself should be fine.
The labor will be significantly less to replace the headgasket than to drop the entire motor. Not to mention that if you motor only has 97k miles on it, that is the preferable motor to have. |