Insight
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.