Table of contents: Glow plugs ↓ Tightening torques for threaded… ↓
Glow plugs
Current consumption - 8 A per spark plug
Tightening torques for threaded connections Nm
Glow plugs - 15
To facilitate cold starting, diesel models are equipped with a preheating system, which includes glow plugs, a control unit (built into the engine control unit), indicator installed on the front panel and connecting wiring.
Spark plugs are miniature electric heating elements enclosed in a metal housing with a tip on one side and an outlet on the other. A glow plug is screwed into the intake tract of each cylinder, installed in the path of the fuel torch. If voltage is applied to the spark plug, the fuel, passing through the heated or red-hot tip, heats up, reaching the optimum temperature in the combustion chamber.
The glow duration of the spark plugs is regulated by a command from the control unit, which monitors the engine temperature using signals from the coolant temperature sensor.
The indicator light on the instrument panel indicates that the spark plugs are warming up. The light goes out when the temperature reaches a level sufficient to start the engine, but the spark plugs continue to be supplied with power for some time before starting. If there is no attempt to start, the power supply to the spark plugs is disconnected so as not to discharge the battery and burn out the spark plugs. If a malfunction occurs in the control system, the indicator starts to flash and the system switches to bypass mode. In this case, you should present the car to an Audi/VAG dealer for diagnostics.
(The original publication in its entirety is posted on the website: «AUDImanual»)