Glow Plug

Glow plugs give diesel engines a boost in the cold weather by acting as an igniter and heating the fuel during the starting process. Diesel engines don't rely on spark plugs for combustion, and instead are fired by heat generated by compression. When a diesel engine has sat idle and cooled down, especially in the coldest months, the air in the diesel engine may not be hot enough to combust. The glow plugs heat the cylinder to aid in starting the engine. If your diesel experiences hard idling, excessive white smoke, or fails to start in the cold, your glow plugs should be tested. If you're ready to replace your glow plugs, visit O'Reilly Auto Parts for a complete line of diesel repair parts.