One tool every gearhead should have and why

mopar56 said
Hear is a good one, its not exactly in the tool box but on my list, I guy comes in to my store the other day and he has ( and is selling for 300 bucks CDN ) a small thermo imaging camera that plugs into your cell phone it is about 1" square he uses it for looking for hot spots in wires, coils, cyls etc, the image is projected directly on your smart phone screen, now I gotta say I am not a geeky tech guy at all but that is cool as hell and on my list particularly useful with multi coil set ups on some of the engines I work on.

You can likely do that for less. Google infrared photography, "anti aliasing filter." On many camers, get yourself a cheap one........you can remove the anti aliasing filter behind the lens and just in front of the sensor. This essentially turns the camera into a "reversable" infrared camera. I say "reversable" because you can use it normally so long as you THEN add a filter to the front of the lens

As an example, this old Canon Xt is right now on Spokane CL for 100 bucks complete with extra batteries and lens, allegedly operational: