Here are the channels I follow which have a science/engineering slant:
The Action Lab - Short science experiments.
driving 4 answers - Bosnian dude covers automotive engineering with outstanding explanations.
minutephysics - Short physics topics.
Practical Engineering - Civil engineering, often analyzing disasters.
Real Engineering - Irish dude covers assorted engineering topics.
SmarterEveryDay - A must see for anyone interested in engineering. The dude gets invited to places the public can't go, e.g. a USN sub on active duty at the North Pole, probably owing to incredibly friendly, knowledgable personality. He worked as an engineer for the defense industry, and last I knew was working toward PhD.
Steve Mould - UK dude covers assorted engineering topics and does his own experiments.
Technology Connections - If it is something you encounter in your daily life, he covers it.
Tom Scott -UK dude covers assorted topics, and some involve engineering, in his travels
Tech Ingredients - Dude has huge home lab and probably spends more money than any other channel, doing incredibly complex experiments involving chemistry/engineering/physics, often with his adult sons. He is cagey about his identity, but after watching all his videos, I finally figured it out. He is an MD.
Veritasium - Physics PhD with Australian background. Physics/engineering topics.
SciShow - Short topics on cutting edge science, with a new video almost every day.
Applied Science - Only occasionally puts out videos, very lab focused.
3Blue1Brown - Purely mathematics focused. The most pleasant speaking voice imaginable, and the most amazing moving graphics to show the concepts. The math prof I wish I'd had in engineering school.