Why does the engine stall if the clutch is released too quickly?

When starting a manual transmission vehicle, everyone knows that if the clutch is released too quickly, the engine will stall. However, some people don't understand why it stalls or whether this type of stalling can damage the engine.

First, let's understand how the clutch works.

The clutch is an intermediate mechanism between the engine and the transmission. Its main function is to achieve smooth engagement and disengagement between the engine and the transmission so that power can be transmitted smoothly during starting, shifting and parking. When the clutch pedal is pressed, the clutch is disengaged. Although the engine is still running, its power is no longer transmitted to the transmission. When the clutch pedal is released, the clutch engages, and the engine's power begins to be transmitted to the transmission, driving the vehicle forward.

So, why does releasing the clutch too quickly cause the engine to stall? This is mainly because the speed difference between the engine and the transmission needs to be gradually reduced and converged during the clutch engagement process. If the clutch is lifted too quickly, the speed difference between the engine and the transmission becomes very large in an instant, and the engine's output torque cannot quickly match the transmission's requirements.

In simple terms, the engine does not have a lot of torque when it is idling. When a large load is suddenly applied to it, at that moment, it does not have enough power to drive the load to rotate together, so it cannot rotate, resulting in stalling.

Why won't the engine stall if you release the clutch slowly?

Because the engine load does not increase suddenly when you release the clutch slowly, but increases little by little. The clutch is not fully engaged when you release it slowly, and the clutch plate and flywheel are in a state of rotating and sliding at the same time. When the vehicle starts successfully, the wheels start to rotate, and the speed difference between the engine and the transmission gradually decreases. When you release the clutch completely, the engine will not stall, and the engine can drive the load to run.

Of course, releasing the clutch quickly doesn't always cause the engine to stall; as long as the engine's torque is sufficient.

Will frequent stalling like this harm the engine?

There will be an impact, because this is not a normal flameout, the engine is resisted and the speed suddenly drops to zero. This will cause certain impacts on components such as the crankshaft and connecting rod, which will cause increased wear of these components in the long run.

Secondly, the fuel mixture inside the engine will not be completely burned, resulting in carbon deposits and affecting the performance of the engine.

In addition, it may also cause abnormal operation of the engine's fuel supply system, ignition system and other components, further exacerbating engine damage.