Description and operating principle of the glow plug system (Defender 2007+)

Arrangement of elements

Pos.	Spare part number	Name
1	-	Glow plug wire
2	-	Glow plug(s)

Review

The glow plugs are located on the side of the cylinder head and serve to facilitate engine starting and improve engine efficiency. The glow plugs and glow plug indicator light are controlled by the engine control module (ECM).

Glow plugs preheat the combustion chambers, which facilitates starting a cold engine. During preheating, the ECM receives an engine temperature signal from the cylinder head temperature (CHT) sensor, which determines the duration of the preheating process. The lower the temperature, the longer the preheating time. The maximum preheating time of 8 seconds corresponds to a temperature of -20°C or lower. At temperatures above 80°C, preheating is not used.

After the engine starts, the glow plugs begin the post-glow phase. The post-glow phase helps improve idle performance and reduce hydrocarbon emissions by providing more efficient combustion immediately after starting. The post-glow phase only operates at engine speeds below 2500 rpm; at frequencies above this, the post-heating phase is interrupted to extend the life of the glow plugs. The maximum duration of the post-heating phase, equal to 30 seconds, corresponds to a temperature of -20°C or lower. At temperatures above 50°C, the post-heating phase is absent.

(Data taken from the website: www.LRman.ru)