Where are glow plugs typically installed?

Glow plugs are typically installed in the intake manifolds of a diesel engine. Their primary purpose is to preheat the air/fuel mixture to facilitate easier ignition during cold starts. By heating the combustion chamber, glow plugs help ensure that the fuel ignites properly, enhancing engine performance and reducing emissions, especially in low-temperature conditions.

The placement in the intake manifold positions the glow plugs to directly impact the air entering the cylinders, making them effective for starting the engine in colder weather. Unlike other components such as those found in exhaust manifolds, oil pans, or associated with fuel injectors, glow plugs have a critical function specifically tied to the combustion process during starting rather than operating after the engine is running or managing the exhaust gases. This underscores their unique role in the functionality of diesel engines compared to other components that serve entirely different purposes.