Autolite glow plugs are known for dependability and long-lasting performance. Diesel engines depend on high heat in the combustion chamber for the fuel to ignite. There is very little heat while cold-starting a diesel engine and the engine is unable to start. As you turn the ignition switch, the glow plug warms the combustion chamber, making the conditions favorable for the fuel to ignite. These glow plugs are used in a variety of diesel applications. If you're experiencing problems starting your diesel engine, it may have burnt-out glow plugs.