In this how to video, you will learn how to install and replace the glow plug in your RC car. Glow plugs are used to ignite the fuel in the engine. A glow ignition makes the filament in the plug red hot. To check if the glow plug works, place it on the ignition and check if the filament is bright red. This is very easy, as you just need a 4 way wrench. Slide it in the engine and take the glow plug out by spinning the wrench counter clockwise. Once this is done, place the new glow plug in and use the wrench to secure it back in with a clockwise rotation. Do not over-tighten it. Now you are ready to use your engine.