Does Revving the Engine in Neutral Harm the Car?

[LaMorgan]

Revving the engine in neutral can affect the car in the following two scenarios: 1. Short-term: Short-term operation will not harm the engine as long as the RPM is not excessively high, and it will have no impact on the engine. 2. Long-term: Prolonged revving in neutral can cause severe incomplete combustion. If this partially unburned fuel mixture ignites outside the cylinder, it may lead to vehicle self-ignition. Additionally, incomplete combustion is more likely to produce carbon deposits, which can clog the catalytic converter, resulting in abnormal high temperatures in the converter. These high temperatures may cause wiring to self-ignite and damage the engine.