Pre and post-heating Glow Plugs

Pre- and Post-Heating Glow Plugs: what happens when they don’t work properly

Glow plugs are a critical component of diesel engines: they regulate the combustion process and play a key role in controlling emissions, especially in modern vehicles.

Installed in the cylinder head, with a ceramic or metal heating tip extending directly into the combustion chamber, pre- and post-heating glow plugs operate during start-up and help optimize engine performance in the first minutes of operation.

When they do not function properly, the following issues may occur:

• Dedicated warning light or check engine light activation
• White/grey smoke from the exhaust during the first minutes
• Engine instability (rough idle, vibrations)

Malfunctions are generally caused by:

• Poor material quality
• Low manufacturing standards
• Overheating
• Excess voltage
• Damage to the heating tip or other components

Prompt replacement is essential to restore proper vehicle performance and reliability.