Defects - Metal rod glow plugs

The appearance of a glow plug can provide clues as to possible causes of damage. Here you can see the most important defects and learn what they tell you.

Overheating damage to metal rod glow plugs arises if the point of injection time or spray pattern is not set correctly, the wrong fuel quantity is injected or oil penetrates into the combustion chamber.
Such a defect indicates overheating damage to metal rod glow plugs

Overheating damage

Such a defect normally arises if the point of injection time or spray pattern is not set correctly, the wrong fuel quantity is injected or oil penetrates into the combustion chamber.

Overheating damage to metal rod glow plugs arises if the point of injection time or spray pattern is not set correctly, the wrong fuel quantity is injected or oil penetrates into the combustion chamber.
The "blown-out" glow tube is the typical result of overvoltage damage

Overvoltage damage

A "blown-out" glow tube is the result of using the wrong glow plug (12 volts instead of 24 volts), the control unit is defective or the alternator generates too much voltage.

A broken glow rod is an indication of an incorrect injection point, the incorrect injection pattern or a poorly set flow rate.
A broken glow rod is an indication of an incorrect injection point, the incorrect injection pattern or a poorly set flow rate

Broken glow rod

If the glow rod has broken, it may be a result of the incorrect point of injection time, the wrong spray pattern or a poorly set flow rate.

Incorrect use of the tool can result in breaks of the glow plug at the housing or the connection.
Incorrect use of the tool can result in breaks of the glow plug at the housing or the connection

Breaks on the case or connection

In this case it was obviously the wrong tightening torque or the wrench was not used correctly.

Incorrect torques can also result in the break of a glow plug.
Incorrect torques can also result in the break of a glow plug

Incorrect torques can also result in the break of a glow plug.