Heating element melted/broken off

Cause:

• Incorrect injection timing
• Carbon buildup on nozzles
• Engine damage (due to valve damage, piston seizure, seized piston rings, etc.)
• Leaking nozzles

Effect:

• Glow plug casting overheats, melts, or breaks

Corrective Action:

• Check injection system (i.e. nozzle-and-holder assembly)
• Check/reset injection timing
• Check for engine damage
• Replace with Bosch quality glow plugs

Depressions in heating element

Cause:

• Operation with excessively high voltage, i.e. vehicle jump started
• Excessively long energization (power supply/preheating relay)
• Incorrect post-glow with running motor
• Incorrect glow plug installed (no post-glow capability)
• Increased alternator voltage

Effect:

• Break in heating wire

Corrective Action:

• Check pre-glow system
• Replace preheating-time relay
• Replace with Bosch quality glow plugs.

Ceramic heating element broken

Cause:

• Incorrect injection timing
• incorrect injector spray pattern
• Supply voltage too high (incorrect application)

Effect:

• Ceramic heating element becomes too hot and breaks.

Corrective Action:

• Check engine for oil consumption
• Check control unit function
• Check/reset injection timing
• Replace with Bosch quality glow plugs