Engineering quests

Quests that require skill in Engineering; reward or make available for purchase at least one schematic.

Trainers

 * The Zapthrottle Mote Extractor!

Factions
Engineering quests available upon attaining neutral or more favorable reputation with the quest giver's faction.

Steamwheedle Cartel

 * Flash Bomb requires Engineering and completion of Pearl Diving from Rigglefuzz in Badlands.
 * Snake Burst Firework is a BoP Unlimited sale recipe available upon completion of: Zapped Giants (quest) and Fuel for the Zapping from Zorbin Fandazzle in Feralas.
 * Tranquil Mechanical Yeti requires level 55, 250 skill and completion of: Are We There, Yeti? (quest), Are We There, Yeti? (2) and Are We There, Yeti? (3) from Umi Rumplesnicker in Everlook.

Instances
Engineering quests involving Instances.

Gnomeregan

 * Minor Recombobulator can be learned from Matrix Punchograph 3005-B with 140 skill (also requires Yellow Punch Card?). Alternatively, it is also a Limited Sale Recipe sold by Fradd Swiftgear in Sundown Marsh and Namdo Bizzfizzle in Gnomeregan.
 * Discombobulator Ray can be learned from Matrix Punchograph 3005-D with 160 skill and possession of Security DELTA Data Access Card. Alternatively, it is also a Boss drop from Mekgineer Thermaplugg in Gnomeregan.
 * Goblin Transponder is available to Horde Engineers upon acceptance of Rig Wars from Nogg in Orgrimmar and completion of: Chief Engineer Scooty from Sovik in Orgrimmar and Gnomer-gooooone! from Scooty in Booty Bay.

Seasonal Events
Engineering quests available during seasonal events.

Lunar Festival

 * Firework Launcher is a quest reward upon completion of Firework Launcher (quest) from Fariel Starsong in Nighthaven, Moonglade.
 * Small Rocket Recipes contains BoP schematics for Small Blue Rocket, Small Green Rocket and Small Red Rocket. The recipes are a quest reward upon completion of Small Rockets from Fariel Starsong in Nighthaven, Moonglade.
 * Large Rocket Recipes contains BoP schematics for Large Blue Rocket, Large Green Rocket and Large Red Rocket.  The recipes are a quest reward upon completion of Large Rockets from Fariel Starsong in Nighthaven, Moonglade.
 * Cluster Launcher is a quest reward upon completion of Cluster Launcher (quest) from Fariel Starsong in Nighthaven, Moonglade.
 * Cluster Rocket Recipes contains BoP schematics for Blue Rocket Cluster, Green Rocket Cluster and Red Rocket Cluster. The recipes are a quest reward upon completion of Cluster Rockets from Fariel Starsong in Nighthaven, Moonglade.
 * Large Cluster Rocket Recipes contains BoP schematics for Large Blue Rocket Cluster, Large Green Rocket Cluster and Large Red Rocket Cluster. The recipes are a quest reward upon completion of Large Cluster Rockets from Fariel Starsong in Nighthaven, Moonglade.

Winter Veil

 * Snowmaster 9000 is one of six random primary profession recipes contained inside Smokywood Pastures Special Gift. The gift is a quest reward upon completion of: Stolen Winter Veil Treats, You're a Mean One... and A Smokywood Pastures' Thank You! from either Wulmort Jinglepocket in Ironforge or Kaymard Copperpinch in Orgrimmar.

Drops

 * Scrapbot Construction Kit requires Engineering and completion of SCRAP-E (quest) which starts from SCRAP-E Access Card, a drop from Library Guardian, and ends with SCRAP-E in The Storm Peaks.

Legion
As with all professions in Legion, Engineering has its own questline through which you learn most of the recipes.