What is indicated by a rising EGT during engine start?

A rising EGT (Exhaust Gas Temperature) during engine start is an indication of normal engine operation. During the starting phase, as fuel is introduced into the combustion chamber and ignites, the combustion process generates heat, which raises the exhaust gas temperature. This is expected behavior as the engine transitions from a cold start to its operational temperature.

Monitoring EGT is crucial, as it helps ensure the engine is operating within safe performance parameters. If everything is functioning correctly during start-up, an increase in temperature reflects fuel combustion and typical engine acceleration.

In contrast, if there were insufficient fuel supply, the EGT would not rise adequately; an indication of engine failure could present as a significant drop in EGT or failure to rise; excessive exhaust backpressure typically presents as an increase in temperature in later engine stages rather than during the startup phase. Understanding these dynamics is essential for diagnosing engine performance during startup.