Once you've reached the level where you can choose an engineering specialty, you can pick up the quest Gnomish Engineering from an engineering trainer in a capital city. Alliance engineers should see Lilliam Sparkspindle in Stormwind, Tana Lentner in Darnassus, Ockil in the Exodar, or Tinkmaster Overspark in Ironforge.

What level can you learn gnomish engineering?

Remember, you need 200 engineering skill and must be at least level 20 to be eligible. Gnome Engineering (Quest).

Where do I learn gnomish engineering horde vanilla?

For horde, this quest is given by the engineering trainer in Orgrimmar, on the Drag.