vaporlock

Vapor lock is a phenomenon that occurs when a liquid-based system, most commonly fuel systems in internal combustion engines, experiences a blockage caused by the vaporization of the liquid. This vaporization creates a vapor bubble within a line or component that is designed to carry liquid. When a vapor bubble forms, it obstructs the flow of the liquid, leading to a loss of pressure or complete stoppage of flow.

The most common cause of vapor lock is excessive heat. In automotive fuel systems, this can happen when the engine compartment becomes extremely hot, such as during prolonged idling or when driving in very warm weather. Heat can be transmitted from the engine or exhaust components to the fuel lines. If the fuel's temperature rises above its boiling point, it will vaporize, creating the problematic vapor bubble. Another contributing factor can be a drop in pressure within the fuel system, which lowers the boiling point of the fuel.

The symptoms of vapor lock can vary depending on the severity. In vehicles, it often manifests as engine stalling, difficulty starting the engine after it has been heated, or a rough-running engine. The engine may sputter or hesitate due to insufficient fuel delivery.

To prevent vapor lock, engineers design fuel systems with considerations for heat dissipation and pressure regulation. Using fuels with higher boiling points or adding anti-vapor lock additives can also help. In older vehicles, shielded fuel lines or relocating fuel lines away from heat sources were common solutions. If vapor lock occurs, allowing the system to cool down will typically resolve the issue as the vapor condenses back into a liquid, restoring normal flow.