Preheating device for diesel engines (Opel Omega B)

On a cold engine, the autoignition temperature by compression is not reached, so the engine must be warmed up.

For this purpose, one glow plug is screwed into each combustion chamber. The glow plug consists of a housing with a pressed-in heating rod. As soon as voltage is applied, the heating rod winding heats up to +850°C within a few seconds, reducing the warm-up time before starting to 5 seconds. After the pre-heating system indicator lamp on the instrument panel goes out, the engine can be started.

Pre-glow duration, as well as automatic follow-up after start (in about 20 seconds), is regulated by the pre-heating relay using the DDE control unit.