We may receive a commission on purchases made from links. The glow plugs in a diesel are like the spark plugs in a gasoline ...

Two such features are a diesel engine's glow plugs and intake heaters. Both were designed to help diesel fuel combustion, particularly when the engine or ambient air are cold. An intake heater ...

Thus, many diesel engines have what are known as glow plugs — essentially little electric heaters — that can heat the air in the cylinder to a higher temperature before the engine is started.