you dont have to be an engineer to work on cars/engines. in fact id say 95+% of engineers dont know jack about working on cars or engines in general.
dive right in iverson. thats how you learn.
I pulled apart my first engine long before I took any specific engineering courses.
and yes manufacturing is kinda lame. lol camtach.
I think if you have the degree you can still be called an engineer...but you cant call your self a professional/must make the pt you dont have your peng yet imho.