@asaj2210 Engineer is very hard to approach because of Stun mines and Turret. You should keep your distance and try to stay out of the way of his spam.
Sometimes, its better to destroy the turret first rather than the engineer. If you can't kill the Engi because he's corner peeking or has too much HP, destroying the Turret is good way to stop his spam.
Watch out for Engineers that know how to use Double Time. Engineers can use the speed boost to close distances and stun you.
Any abilities that can deny areas (like Goatify, Bean Bomb, or Super Sap Trap) will be really good at stopping both the Engineer and his turret.
If you are playing Chomper, Engi is one of his worst matchups. Grody Goop can deny abilites, and Chomper can snipe with Slobber Shot. Otherwise, Chomper has very few good options against him.